I made FullScreenMario.com, now celebrating 2 million visits. AMA!
Hey Reddit, my name's Josh Goldberg; I'm the programmer behind FullScreenMario.com - an HTML5 remake of Nintendo's Super Mario Bros. You can play it for yourself on http://www.fullscreenmario.com, or grab the source code on http://www.github.com/DiogenesTheCynic/FullScreenMario (please post all bug reports there as well, after checking if they're already posted). Go ahead and AMA!
4:45 update: All right everyone, thanks for the great questions! Keanu Reaves is doing an AMA so we're done here.