[BlackEleven]

One thing you may want to consider when buying your lens that hasn't yet been mentioned is the crop factor. An XTi has a crop factor of 1.6x (I believe its 1.5x for the D80, but someone else can verfiy that for you).

So if you buy a, say 17-85mm lens, then the effective range is actually 27-136mm. So you end up losing a bit of range on the wide angle and gaining a bit of zoom.

Also, like Neeper said, its always nice to have a f-stop of f/2.8 or better. Remember even if the lens doesn't have IS, you can stop down to speed up the shutter, and therefore there's not a need to hold it as steady. The f-stop is also ideal for low-light situations and creating a shallow depth of field. Don't fall into the trap of just looking at the range of the lens, the f-stop is just as, if not more important.

Edit: Also, I should note that I also buy my stuff from B&H photo online. They ship to Canada and you can get it shipped with USPS (to avoid brokerage fees). In addition, cameras and lenses are duty-free items, so when you pick it up all you have you pay is the GST (and PST if you're outside AB). With the high Canadian dollar and the lower American prices, you can really get some great deals.