Hey, I was looking at lenses to buy for my XTi... I currently use a Canon 28-90mm USM II - from a Rebel Ti film camera. I've found that I'd like to move on and upgrade a bit without spending too much. Here's what I've narrowed it down to: Option 1) Tamron 17-50mm lens f/2.8 - Appealing because of the quality for the price. This is basically the top of my budget. It doesn't the Image Stabilizer that my next option does, IS is that I could definitely utilize... but will the larger aperture make up for it? Option 2) Canon 18-55mm lens and the Canon 50mm f/1.8 lens. Really only because the 18-55 has IS... which I know would help me in almost every situation. Then I'd also be able to get the 50mm f/1.8 lens just since I've heard good things about it and I'd have a little bit more money left over. Option 3) Sigma 17-70 - Not so appealing unless someone convinces me otherwise. -I was basically convinced to get the Tamron but then the idea of the image stabilizer made me rethink my decision. Uhh... suggestions?