This is entirely for fun and is not really complete in any way. No support for SChip games and scrolling.
Keys are mapped to the numerical keypad (0-9), Insert, Delete, Home, End, PageUp and PageDown.
The keys are shuffled around depending on the game, so push all buttons until you find which ones do what.
Some games are not working, or are working in ways that I do not comprehend. Also, some need a page reload to work.

The roms are parsed by a PHP script and served to the javascript as an array of hex values.

The emulation is somewhat based on the chip8dynarec project (http://code.google.com/p/chip8dynarec/source/browse)
Also check out Robert Gamble's javascript Chip-8 emulator which is more complete: (http://www.elephantsneverforget.co.uk/rg/chip8.html)
Info on Chip-8: http://en.wikipedia.org/wiki/CHIP-8

Comments: go here