I have just purchased a 550d with the 18 to 55 kit lens. I also have the 50mm f18.Ive been having a lot of fun learning how to fly it. I have now decided that i might get a bigger zoom,perhaps something like the Tamron SP AF70-300mm F/4-5.6 Di VC USD and was wondering if anybody here has this lens and what they think of it. Cheers