Ritz has got a great deal on 4GB and 8GB SD cards going on right now:
Kingston 8GB SDHC Class 6 Flash Card – $18.99
According to Ritz, these prices are only good November 1-8.
I just picked up one of these Kingston 8GB a couple of weeks ago (although I paid a little more) and I’m pretty happy with it’s performance in the Rebel XSi (holds about 550 RAW images); however, it’s not as speedy as a SanDisk Extreme III card. Still, if you don’t need the max-burst queue, this is pretty cheap storage.