Yeah, there were some classic comments last sunday. One I always like was:
When you look at the stars and galaxies and the orbits of the planets, you can clearly see that a god of oganization created it. Scientists say that everything came about from an explosion in the "big bang" (said with a very snide tone) but what do you get from an explosion? Chaos, not order.
That one had me pretty pissed off, since that's a complete misunderstanding of what the big bang is. Also, it's not really difficult to demonstrate the concept that gravity would naturally cause things to coalesce into something resembling an equilibrium after a while. As the OP mentioned, asteroid collisions, aptly demonstrate that things aren't all that ordered. Whats more, it's very likely that early planets are often sent crashing into their stars. Hell, even galaxies collide rather frequently, and our own galaxy is due for a collision with andromeda in about 4 billion years. Not so ordered afterall.
Another great moment was when one elder accidentially disproved the story of the flood: He said "what I never understood was what they did with all the insects - there's millions of species of insects and they don't interbreed...they couldn't possibly have all fit on the ark" It's so sad, this elder is relatively clever (another of his favorite comments is that he wants to ask god what was up with them dinosaurs) and seems to see the holes in the bible and the religion but he is so absolutely loyal to the organization that it's disgusting.
As for the "evolution is just a theory" argument, my counterpoint is that it is "just" a theory in exactly the same way that gravity is just a theory. We don't fully understand the mechanisms behind gravity, and there are many different explanations of how gravity might work (and physicists often get into rather impassioned debates about which must be the best explanation). Yet, we don't go around arguing that gravity never happened, because we can see the evidence everywhere. Just like there's evidence for evolution everywhere.
The parallel with gravity also works when creationists make use of the inflation of conflict logical falacy (saying, even the experts don't agree on how evolution works, so why should I believe it?). Experts don't agree on how gravity works, but we all believe in it. The only difference between evolution and gravity is that the idea of gravity has been around longer, and the evidence for it takes less effort to see. Oh, and it doesn't directly disprove the bible (though it does indirectly disprove many accounts in the bible)