Hi, I am afraid there's no easy way to get true collision detection working (especially at the triangle level). There are a few physics lib you can look into like WoW or Jiglib. Of course adding physics will complicate things and affect performance. I have seen demos of 3D apps using 2D physics (Box2D). HelloEnjoy was such a case (objects only interact on x and y, not z).
If precision is not an issue using a simple bounding radius and checking distance between objects. It should do the trick. I am working on a 3D Asteroid like game on my spare time and used this technique. Surprisingly, it works great! Here's the demo http://www.wemakedotcoms.com/projects/crapteroids/v0.2/ ath. Jerome.
