RE: SD Cards...
When you're buying SD cards, or any flash memory for that matter, make sure you get good, name brand stuff like SanDisk. Using cheap memory is a recipe for disaster as they corrupt and eventually go bad much easier and quicker than high quality cards. Just something to keep in mind - you would hate to get 30 or 40 photos only to find out they you can't retrieve them off the card.
Furthermore, the vast majority of digital cameras these days are using SD cards. In fact, you can barely find any new cameras running Compact Flash anymore. When I was looking for cards for my Cuddeback Excite I had a terrible time finding anything less than 1 GB, which are still running in the $80 range per card. Sony has their own proprietary memory, the "Memory Stick", but just about everyone else seems to be on SD or XD cards.