Are you looking for something other than the obvious "use a case or put it in a sleeve?" – bmike♦Mar 8 '12 at 16:34
Yes I am. If you have the keys in your pocket or lose change, they tend to scratch the lens face even if you have put it in case - I don't know of a case that covers the face of the lens. – Raj MoreMar 8 '12 at 18:23
Maybe consider not putting the phone in the same pocket as change and keys. ;) – RichardMar 8 '12 at 20:54