there are tons of ways to do collision detection. The simplest way is to just check if the bounding boxes (the smallest containing rectangle) of your bitmaps overlap. That's fast to do, but it's a problem if you're using something like circles, because their boxes can overlap even if they're not actually touching.

Checking to see if the pixels of one object touch the pixels of another is the most accurate, obviously, but it can be a very slow process.

Google around for 2D collision detection, and you should find some stuff to read. Be sure to look for 2D collision detection, because 3D collision detection is even more documented, but the topics are pretty unrelated.

Thanks for the advice. I'll be working on this one late tonight.

Enjoy

I definately use the bounding box or bounding circle approach though.