Credit:
What does all that have to do with Google's web browser, Chrome? Well, a chap named Ben Firshman ported a NES emulator called vNES into JavaScript, creating JSNES. Yes, it works in Firefox 3.5 and in Safari 4, but thanks to its JavaScript optimizations, it runs about 10 times faster in Chrome.
To play, you only need to open this address in Google Chrome, and choose a ROM. I've tried out a couple of games and gotten an average FPS of around 50, compared to an unplayable 5 in Firefox.
Besides helping you kill some time, this exercise is cool because it really makes you see that all those under the hood optimizations in the new Chrome aren't just hype.