[Bigtime]

Originally Posted by Thor

I'm trying to keep it around $500, but here's a few I've spotted that sound promising:

Canon EF 70-300mm f/4.0-5.6IS USM Lens $699

That is the second lens I bought for my XSi. I love it, the image stabilization is very good, and has two modes if you are panning a moving subject.

I use it for a lot of aviation photography and construction shots from my balcony: