Since the A760 is running J2ME, it can handle most generic J2ME applications (also called midlets) available on the 'net. I've downloaded and tried about 50 so far, at various levels.
Good places I found for J2ME apps are:
Watch out for platform-specific midlets (there seem to be an enormous number of Siemens-specific midlets floating around, for example). They won't work at all on the A760.
The most irritating feature of some midlets is that they expect to run on a phone with a numeric keypad. Since the A760 doesn't have a keypad at all, many midlets that expect to find number keys just don't work at all. However, I did manage to get Spruce Tetris working -- it has both keypad and touchscreen input options :) On the other hand, the killer app -- Floyd SSH doesn't work due to this limitation. Anyone good at hacking J2ME who can fix Floyd SSH to take touchscreen input? Half my kingdom and my daughter's hand in marriage would be a bit excessive, but I would definitely stand him/her a glass of beer :)