You could go much higher in ISO than 800, with a good noise reduction software (such as DXO or Light Room) ISO 3200 is quite usable. Much better to have a noisy shot than a blured one. I have taken properly exposed shots up to 12,800 on my 60D (same sensor as your t2i) and it's still good for web sized images, actually it's quite good at that resolution, and a kinda noisy 8x10 but not bad.

John.