My good old (oops Young) friend from AAS has set-up a Themes site for Symbian phones like Nokia 6600 (and eventually the Nokia 7650/3650’s).
The site is called Symbian Themes and features a nice layout.
The site is still in Beta stage, but I feel has a lot of potential if J2K can offer the 7650 user Themes, even if they are limited due to memory restraints of the phone.
One small point, I was apparently the 50th visitor!
Good Luck J2K