I bought my Opteks's off ebay and they work great, I use the polorizing lense just about everywhere since I mostly shoot outdoors. The one question I have is what is the best way to clean the lenses? Right now I just use water and lense cloth like the ones you clean sunglasses with. Should I be using some kind of spray or is water alright?

There is a plethora of info already posted about lens cleaning. A simple search will probably give you more info than you ever wanted!

RB