I've been getting annoyed at being unable to assign my ringtones to my gmail synced contacts. Something that was a non issue on my old faithful G1. Samsung, it seems, has seen fit to screw with the contact management making it necessary to have a contact in the phone memory proper to assign a custom ringtone. I have found a simple solution. Download Ringo Lite from the market place. It will allow you to assign ringtones to any contact on the phone in a really simple manner and the app is free. It has other features like assigning rings to sms messages and stuff but I don't care about that or need that. But for setting ringtones it works just dandy.