fotomom - For all around I would say the Sigma 24-70mm f/2.8 http://bit.ly/dXynaO
It's pretty versatile and we use it when we only want to take one lens.
Most of the lenses I use are for full frame and they work just fine. I haven't noticed any difference between those and the crop designed lenses. (besides magnification of course) :D
They're cookin'! I'm gonna need more than one cat if I'm gonna try this:-)
I have my dad's 40D. I can't take a decent shot with it. I think it is that he had film lenses for it vs. buying lenses dfesigned to work with it. Can you recommend your favorite all around lens that you use?