[pwrbkdude]

well i tend to shoot and dusk and at night frequently, and on long exposures even with a tripod sometimes there are small amounts of shake, so that is the main reason for desiring IS.

I am also thinking of a nice long lens for wildlife photography, and on that lends USM and IS are almost a requirement from what I understand???

Sorry for being a bit of a n00b... I've always just shot for the fun of it, but now am taking it as a bit more serious hobby as everyone keeps telling me I should do something with my photos!