i'm getting kind of tired of the 18-55mm kit lens of my canon t2i. i've been to a couple of grand-am and ALMS races, and while the shots itself aren't bad with the kit lens, most of the time i just can't get close enough to the action to get a close-up shot during the race. so i'm looking for an upgrade. a good all-around lens so i don't have to swap lenses all the time. i was hoping to find something good for say $500 - $700 if possible. i usually take panning shots free-handed. obviously a 2.8 f/stop would be great but it gets very pricey in that range... here are three lenses i have come up with so far. Canon EF 70-300mm f/4-5.6 IS USM Lens - $495 Canon EF 70-200mm f/4L USM Telephoto Zoom Lens - $674 Sigma 70-200mm f/2.8 EX DG HSM II Macro Zoom Lens - almost $800... anybody input is appreciated. thanks in advance.