There are alot of Xbox games (over 200!) that are compatible with the xbox 360 provding that you have an xbox360 with a hard-drive.
The list includes games such as:
Splinter Cell, ‘Chaos Theory’,
Star Wars, ‘Knights of the Old Republic’,
Ninja Gaiden Black,
How do I play the games on my xbox 360?
If you have an xbox live silver account – the updating will start automatically when you place the game CD in the console. Alternatively – if you dont have an xbox silver account you can order an update CD from the official xbox website or download the update information and burn it onto a CD.