Throughout college I never did. Really stupid, but it is what it is.
Now, I refuse to unless I happen to have a one night stand type of deal, in which I don't do too often.
It pretty much comes down to the fact that NO sex is worth using a condom over. I have no problem saying "no" if the only option is to wear a rubber.
That's why I carry coat hangers and good stomach-kicking boots in my trunk at all times.