VisualInsight : John Baez's Visual Insight blog focuses on visual aspects of mathematics, and presents material in a way that is both great for broad audiences, and great for leading the mathematically inclined further into the topic. The images are compiled from other mathematicians and programmers.

acko.net : “Hackery, Math, and Design”. Steve Wittens of acko.net wrote the best tutorial on Julia sets I’ve ever seen, and writes fantastic presentations that are sure to inspire a new generation to do away with PowerPoint.

georgehart.com : George W Hart creates varied sculpture based on mathematical principles. His work inspired my video, “I Heart Group Theory and So Can You”, and I recommend that you check out and build his slide together constructions!

markjstock.org : Mark J. Stock produces work based on computational physics. He’s inspired to try new simulations and projects, and to change the techniques I use in my own physics simulations. His youtube channel is full of hypnotizing pieces and slow, sloshing, detailed fluid mechanics simulations.

segerman.org : Henry Segerman is a mathematics professor with a lot of great work, including collaborations with youtuber and artist Vi Hart, and a book, Visualizing Mathematics with 3D Printing

worrydream.com : Bret Victor, a designer who has worked for Apple, tends to focus on interactivity and the visionary futures of user experience. His article Ladder of Abstraction perfectly captures some aspects of thinking that are ubiquitous in mathematics and physics.