kingston 512 is good and cheap. buy.com sells it for under $20 occasionally

if you like spending extra money for no other reason than you got a lot of it, get sandisk ultra ii.

i have both. they both work. only difference is the kingston can't handle unlimited video capture at full res and max. also it can't handle burst mode of 2.5fps for too long. the sandisk swallows all that data like a porn star.