The limit right now is 2 gb. The 4 and 8 gb cards everyone keeps talkin bout are a totally kind of technology. The Pearl might need a new OS and maybe even new hardware to use them. But the 2 gbs work perfectly. Check out buy.com they have microSD cards really cheap there and free shipping most of the time.
Unlocked 8100c w/ 1 gb microSD, BSE total body skin, and rubberized case or silicone skin.