Hey rtf, bouncing isn't terribly hard to do depending on the complexity you want to accomplish.

But the easiest way on a 2D engine is to simply reverse the X or Y velocity(speed) depending if the object hit some thing's sides or top/bottom.

You could also try an 8-way collision system where you would reverse the X & Y velocities when it hits a corner, but that would also mean you will need at least 8 collision check points to make that work.

You can also multiply it by something like 1.10 to give it a bit more of a springy effect as well. Such tricks were used in Scorched Earth for the different wall physics.

More detailed then that, as in hitting a round object for instance, may require a bit of trig to do.