Creationists are willfully ignorant. They have no interest in actually understanding evolution. The only purpose in explaining it to these people online is the possibility that someone else who is ignorant on the subject will read one of these explanations and will perhaps get something out of it. Personally I enjoy hammering Creationists on providing some empirical evidence for how human beings were made out of clay. I say stop letting them determine the battleground. Force them to attempt to back up their absurd Bronze Age myths with something other than 'gawd did it' (they won't, but showing how bereft of intellectual honesty they are is actually quite effective).