My brother talked me into getting the iKlear kit they have at the Apple stores.
Nice big (about 1 sq/ft) cloth for at home, and some travel cleaning packets and a smaller cloth for your pocket/purse.
He said he just refilled the bottle with water, and it works fine on everything (Cinema display, Macbooks, etc).
The only reason to buy it is for the big cloth, even better than the one you get with the iPhone (and bigger than the grey one that you get with the 23" Cinema display).
I used it right before I put iQase screen protectors on 2 iPhones, and I didn't have any dust/hair issues getting trapped under them.
