This long weekend, in spite of the fact that I changed just about every setting I could on my xti to save power, I (of course) ran my battery dead long before the weekend ended. I've decided to get a secondary battery and had some questions about brands. I see on ebay I can get some cheap batteries that are compatable with my camera, have any of you used a camera that is not the one recommended? Any horror stories? Any luck? Besides voiding my warranty I wonder if It's a bad idea to do the money saving thing on this one. The CF cards I got super cheap have been wonderful, but I'm a little iffy about putting a battery in there. Should I just look into getting a battery grip? Is this thread long enough for a very simple question yet?