Before someone seriously bashes you for not "searching" , just head over to wap.crackberry.com and click the forums and go to the blackberry themes section and then the tour sections and poof, a plethora of free and premium themes threads with all the OTA links you could ever dream of.
Posted from my CrackBerry at wapforums.crackberry.com
My bad I forgot to write if there were other websites other than the free themes on crackberry. I used to use a site for my pearl but I can't seem to find it anywhere.