+1 to 70-200 f/4 for outdoor sports and then an 85 1.8 or even a 50 1.4 (depending on how large your gym is--the shots are going to be so small (i assume) by the time they're publised in a year book that if you had to crop in using the 50 the IQ would probably still be adequate). Another benefit is that both those lenses should also be great for shooting student portraits/candids/etc.
I also agree with the suggestions to get another XTi and nicer lenses because glass matters more than the body.
Also, I agree that it's a good idea to find out who is into photography on your campus and has a nice setup--if it turns out some kid already has some fast glass and wants to help out, you might not have to spend as much money to get fast lenses for indoor sports.
Good luck! Your yearbook will definitely be better done than ours usually is--shot mostly with Nikon D40s and kit lenses with the occasional pop up flash used (but luckily not too often). The problem is that it's almost all by people who don't know how to shoot...




It is a very nice FL for under the basket, though, as your sample pic shows.
