Racetrack is a game with very simple rules which nonetheless does a surprisingly good job of simulating the acceleration, braking, and handling of a race car. It can teach not only about inertia and kinematics, but also about optimal racing lines. Racetrack can be played with nothing more than a piece of graph paper and a pen, but there is also an online implementation called Vector Racer.
Just in time for Flash Fun Friday, they came out with a sequel to Pigs Can Fly (previously): Pigs Will Fly! Enjoy!
Sexy Fingers [NSFW funky French 2011 AIDS prevention PSA]. And if that touched you the right way, you'll definitely want to poke around sexyfingers.org [also NSFW but loads of Flash Friday fun]. [more inside]
Flash Fun Friday! Elephant Quest: the best elephants-with-lasers Castlevaniaesque RPG you will play all day. [more inside]
Friday Flash Fun! In Pigs Can Fly, navigate a cute little piggy to the magic potion to help him grow wings and fly away.
OMGpop is potentially all your Flash Fun Fridays come at once. Clones of addictive classic multiplayer games like Bomberman, Pictionary, Tetris, even Mario Kart and Guitar Hero - plus a whole lot more, all wrapped up in an extremely slick interface with an added dash of chat and social networking features. Not yet out of beta, the hype is certainly extensive, but is the business model sound? [more inside]