Yes you can, as long as the 2 games are small enough between them to fit on 1 dvd.
Download craxion 4 and it has a option: multi game disc.
Choose a disc format and press next. Add your iso's press next and create the iso's.
Once burnt onto a dvd you should see a menu with 2 games on when you put it in your xbox.
Yeppers indeedydoo
Matty is right, craxtion 4 is the best app to do it, though you must have .net installed on your pc to use it. You can use craxtion 3.1 still for a ton of games.
Ive actually fit 5 games on a dvd, its actually possible to fit more, as long as its stuff like pure pinball, rollercoaster tycoon etc etc etc.
Dont try to install a multigame disc to your hdd though, it wont load the game after install.
Matty luv yer icon:-)