[richs]

Try Fogdoc.. that stuff is worth its weight in gold.
Or try the old divers secret of using dish soap.. works pretty good and is really cheap!

Actually, you want to put a thin film of J&J Baby Shampoo on the lens, rinse the lens but don't wash off the soap, let it dry and you should be good to go. Divers today use various other anti-fog sprays, but I found baby shampoo worked well and was quite cheep. (I'm a retired SCUBA instructor so I can tell you this works).