Google the URL.
There are some good ones there, but I think you do need to register. They also have a forums section and WAP site if that is your preference. Good luck!
The bphone theme is good. And the unlocked orange today theme.
If you search you shall find.
Posted from my CrackBerry at wapforums.crackberry.com
I've been lovin the bPhone theme (and i'm not even that much of an iphone lover). I just haven't found another theme i've cared for... that has been free. I haven't really looked at any of the paid themes though.
The iPhone and bPhone themes are both pretty sweet. I found one on Eveek called Candy. RIM is vendor and have had no probs with it. Black background and colorful interactive icons. Just thought it might be worth checking out.