What gangsta rap has to do with children's healthcare and mid-century illustration.

We love coloring books and genre-benders of kinds, so today we're turning to five favorite coloring books that transcend the genre's typical numerical age range and instead reach out, with quirk, humor and inspiration, to the eternal kid in all of us.

THE INDIE ROCK COLORING BOOK

British illustrator Andy J. Miller and Montreal-based creative nonprofit Yellow Bird Project capture the true pride point of indie music – quirky, colorful character – in the lovely Indie Rock Coloring Book – a wonderful collection of hand-illustrated activity pages, mazes, connect-the-dots, and coloring pages for indie icons like Bloc Party, The Shins, Iron & Wine, Broken Social Scene, Devendra Banhart, MGMT, The New Pornographers, The National, and Yeah Yeah Yeahs.

All proceeds from the book , which we originally reviewed in 2009, go towards Yellow Bird's inspired mission to raise awareness and funds for meaningful charities and help independent artists find their audience.

GANGSTA RAP COLORING BOOK

From illustrator Anthony "Aye Jay" Morano comes Gangsta Rap Coloring Book – a witty line-drawn hall of fame of gansta rap, featuring 48 pages of the genre's superstars, from Notorious B.I.G. to Compton and just about everyone who's anyone in between.

It's also worth noting that Morano self-published the book, an admirable feat as we continue to contemplate the future of publishing models.

The book is part of a trilogy, including Heavy Metal Fun Time Activity Book and Punk Rock Fun Time Activity Book.

BETWEEN THE LINES

Nonprofit RxArt is out to harness the healing power of art in helping sick children feel better by placing work by leading contemporary artists, from Jeff Koons to Will Cotton to Jason Middlebrook, in children's healthcare facilities. Every year, they publish Between The Lines – a lovely coloring book 100% of proceeds from which go towards funding these inspired hospital projects. The latest edition of the book features over 50 original line drawings by some of today's most celebrated contemporary artists, including Takashi Murakami, Ed Ruscha and Cynthia Rowley, plus a series of delightfully vibrant stickers designed by Nate Lowman and Mickalene Thomas.

Catch our full review, with background on RxArt's phenomenal work, here.

THE WUGGLY UMPS AND OTHER DELIGHTS

We love the Tim-Burtonesque work of prolific midcentury illustrator Edward Gorey (1925-2010). There's something darkly delightful about the mismatch between his grim aesthetic and his proclivity for "children's" books. We recently gushed over his fantastic alphabet book , but it doesn't end there: The Wuggly Ump and Other Delights Coloring Book is an eclectic menagerie of 22 beasts and creatures from Gorey's most beloved books. The title comes from on of Gorey's best-known monsters, an Ump renowned for its Wuggliness.

THE SNEAKER COLORING BOOK

The Sneaker Coloring Book for grown-ups invites you to reimagine the 100 most popular sneaker designs from 1916 to the present by 18 major brands, including Adidas, Converse, New Balance, Nike, Onitsuka Tiger, Puma, Reebok, and Vans. Each full-page silhouette is removable for framing, and a fascinating introduction traces the history of the "sport shoe" from Charles Goodyear's 1840s invention of vulcanization to its pivotal role in skate and hip-hop culture.

The Sneaker Coloring Book is the work of Daniel Jarosch and Henrik Klingel of Berlin-based design studio PKNTS.

What ugly ampersands have to do with wayfinding and vintage pictograms.

We're big proponents of open source as an enabler of both creative expression and innovation. And while the ethos has come of age in the technology sphere, with posterchildren like Firefox and WordPress, some of its most interesting recent incarnations have been on the creative front. Today, we spotlight three wonderful projects that bring the vision of open-source movement to the world of design.

SIRUCA PICTOGRAM PROJECT

Last week, we looked at the legacy of Isotype – the vintage pictogram-based visual language of the 1930s that sparked the golden age of infographics and infiltrated everything from bathroom signs to traffic signage. Siruca Pictogram Project by designers Stefan Dziallas and Fabrizio Schiavi is an open-source pictogram font, free to download and use, even commercially.

OPEN SOURCE AMPERSANDS

Open Source Ampersands essentially a single-character font – a font file that only contains glyphs for a single character – using the ampersand. Each of the ampersand characters is real text, not an image, and can be selected, copied, pasted and applied CSS to. The ampersands scale as you zoom the page and work in every browser, "even ancient versions of Internet Explorer." The project serves as a statement against licensing limitations on the web and aims to celebrate open standards and open source.

And though the folks at shit ampersand may be less than thrilled with many of the designs, it's still an admirable project.

THE NOUN PROJECT

Visual literacy is an essential necessity of modern life. But some of the most widely recognized symbols of visual language are wrapped in a surprising amount of historical and contextual obscurity. This is where The Noun Project comes in – a wonderful effort to collect, catalog and contextualize the world's visual language.

The site offers an ever-growing range of diverse symbols available for free under a CreativeCommons license. Though many of the popular symbols – from No Parking to Trash to the familiar directional arrows – were designed by the American Institute of Graphic Arts in 1974 with the explicit intention of being in the public domain, finding free, high-quality versions of them online is still a pain. Each symbol on The Noun Project, by contrast, is downloadable as a vector file, the most flexible open-standard format available.

The project, brainchild of LA-based designer and architect Edward Boatman , was funded via Kickstarter and exceeded its $1,500 target nearly tenfold, illustrating the palpable cultural need it's addressing.

In the long run, the project aims to aggregate and organize symbols into useful categories like transportation, web apps, wayfinding, communication and more, as well as initiate design contests around the creation of new symbols for fields, objects and themes of increasing cultural demand, from gluten-free food to Internet connectivity to food trucks.

What the theory of relativity has to do with world government and the ethics of nuclear proliferation.

On Monday, we celebrated Einstein's birthday with Albert Einstein: How I See The World , the fantastic 2006 PBS documentary now free to watch online. His birthday also marked the digitization of seven excellent authorized texts from the Albert Einstein Archives, available for the first time in a common electronic format through a collaboration between the Philosophical Library and digital publisher Open Road.

The World As I See It is a fascinating anthology of Einstein's observations about life, religion, nationalism, and various other personal topics that engaged his mind in the aftermath of WWI. With characteristic blend of wit and idealism, the great genius tackles some of humanity's most timeless dualities like good vs. evil, science vs. religion, activism vs. pacifism and more. The collection paints a portrait of Einstein as he makes sense of his own mind and a rapidly changing world through letters, speeches, articles, and essays written before 1935, including many rare documents.

Without the sense of fellowship with men of like mind, of preoccupation with the objective, the eternally unattainable in the field of art and scientific research, life would have seemed to me empty." ~ Albert Einstein , Forum and Century

Essays In Science gathers Einstein's articles and speeches dissecting the scientific method in his own theoretical discoveries and contextualizing, with palpable admiration and respect, the work of his scientific contemporaries and historical influences, including Johannes Kepler, Isaac Newton, James Clerk Maxwell, Max Planck, and Niels Bohr.

What place does the theoretical physicist’s picture of the world occupy among all these possible pictures? It demands the highest possible standard of rigorous precision in the description of relations, such as only the use of mathematical language can give." ~ Albert Einstein , Principles of Research

Essays In Humanism captures Einstein's philosophical reflections on the pace of progress, including prescient topics like Zionism and the global economy, in a collection of essays written between 1931 and 1950 amidst the aftermath of The Great Depression and the turbulent early days of the Cold War. Particularly timely, in light of the recent devastation in Japan, are his thoughts on the double-edged sword of nuclear proliferation.

What is the situation? The development of technology and of the implements of war has brought about something akin to a shrinking of our planet. Economic interlinking has made the destinies of nations interdependent to a degree far greater than in previous years." ~ Albert Einstein , Towards a World Government

Letters to Solovine: 1906-1955 gathers Einstein's correspondence with Maurice Solovine, his longtime friend and translator, discussing topics across science, politics, philosophy, and religion with remarkable candor and intimacy. Frank, funny and invariably insightful, the letters – which appear in both German and English – offer a rare glimpse of the intersection between Einstein's private self and his public persona.

Men are even more susceptible to suggestion than horses, and each period is dominated by a mood, with the result that most men fail to see the tyrant who rules over them." ~ Albert Einstein , Princeton, April 10, 1938

Letters on Wave Mechanics: Correspondence with H. A. Lorentz, Max Planck, and Erwin Schrodinger may be the most technical of the bunch, but it's no less absorbing a read as we trace the communication between three of the era's greatest scientific minds. Perhaps most fascinatingly, it's a thought-provoking perspective shift in the pace of discovery and the time-scale of scientific – and all, really – communication: Just as The Republic of Letters taught us, an email exchange between today's leading scientists may be near-instantaneous, but the written intellectual debates of yore took weeks and often months for a single idea to be transmitted and responded to, which greatly altered the course of scientific inquiry and debate.

I am as convinced as ever that the wave representation of matter is an incomplete representation of the state of affairs, no matter how practically useful it has proved itself to be." ~ Albert Einstein to Erwin Schrödinger

The Theory of Relativity: and Other Essays features Einstein's seven most most important essays on physics, in which the great thinker takes the reader by the hand and guides her through the layered scientific theory that served as the foundation for his discoveries. Compelling yet digestible, the book offers an essential primer on theoretical physics, the laws of science and of ethics, and the fundamental language of scientific inquiry.

The 'principle of relativity' in its widest sense is contained in the statement: The totality of physical phenomena is of such a character that it gives no basis for the introduction of the concept of 'absolute motion;' or shorter but less precise: There is no absolute motion." ~ Albert Einstein The Theory of Relativity

Out of My Later Years: The Scientist, Philosopher, and Man Portrayed Through His Own Words is a collection of essays on the topics and disciplines that tickled Einstein's fancy. From world government to freedom in research to open education, the book, divided into subject matter sections like "Public Affairs" and"Convictions and Beliefs," is equal parts timely and timeless.

Ethical axioms are found and tested not very differently from the axioms of science. Truth is what stands the test of experience." ~ Albert Einstein , "The Law of Science and the Laws of Ethics"