I got myself a Canon Rebel XSi with the 18-55mm kit lens for Christmas last year. It's my first SLR, and I'm really having a ball with it! Overall, I'm relatively happy with the kit lens. It takes pictures that are good enough for me right now, and the zoom range usually covers my needs. However, I'm finding that I do sometimes need a longer lens. I take the camera with me when I go hiking, and it just doesn't allow me to get close enough to the wildlife. So I'm trying to decide on a new lens, and boy is there a lot to consider! There are two obvious choices that come to mind, the Canon EF-S 18-200mm f/3.5-5.6 IS, or the Canon EF-S 55-250mm f/4.0-5.6 IS. The 18-200mm is a single lens solution and it has internal focusing, but that long zoom range apparently comes with some distortion. The 55-250mm is much cheaper and combines with my existing lens to offer more zoom, but I have to carry two lens and it's a front focus. What do you guys think, is there a clear answer here that I'm too much of a newb to see? Is the distortion in the 18-200mm really something I need to be concerned about? Are there other factors I'm overlooking? Thanks in advance for any advice you guys can throw my way.