I havent used it myself yet but from what I have read about on here I think the product most commonly used is Durabak paint
http://www.durabakcompany.com/marine.htm
Do a search on this site for durabak and you will find all sorts of guys talking about it. I think I just recently read a post by Macojoe where he even said how much he had to buy to do it. Also if I remember there was some debate about it being a little tough on bare feet but it doesnt seem to stop most people.