HELP, I have a Canon Digital Rebel XT 8MP Digital SLR Camera with EF-S 18-55mm f3.5-5.6 Lens (Silver)?

Well for one, make sure you stick with Canon gear. Don't venture off and get something like Vivitar. IF your wanting a great lens go and take a look at Canon website, it has a 28-200mm lens that might be what your looking at getting. www.canonusa.com