Of course I do. Don't you?
Didn't myth busters bust the 5 sec rule?
That was part of George Carlin's comedy skit you quoted.
I don't eat stuff that falls on the floor... though I don't try and tell myself that I have a good reason for it, either. It just seems... gross.
I'll use the 5-second rule for candy, but I throw cauliflower on the floor to get rid of it, not because I want it to make it taste better.