My brother is hooked!
He said its better than a christmas present (which is a shame as I could have saved myself £30....
http://openemu.orgSNES/NES/Gameboy/MegaDrive/Master System on your Mac! My brother is using a PS3 controller, but you can configure your keyboard to work as a controller.
Hopefully in the future they'll add support for Amiga's... Well, I lvd in hope, but this is pretty cool for now!
Happy Christmas!
NB: You have to have game ROM's to play on it, and I currently have none. Although my brother informs me you can just Google them and download them.... Legalities surrounding this are not my area of expertise!