American river map via kottke.
Flexagons
Thanks to another Vi Hart video, this time I’ve learned all about flexagons. They are very fun to make; kind of like a cross between a Möbius strip and an origami fortune teller.
Newroz: A Simple Symmetric 11-Venn Diagram
Article link.
Not really related yet still interesting; someone from slashdot mentions Chernoff faces.
[via Cartesian Product]