Im trying to decide on what lens' I should buy next, and I was hoping I could get everyone's feedback here. I do a wide variety of photography. the main thing I do is church directories and general portraits. I also do indoor event/performance photography so a fast lens is useful. So far I have been using my 50/85 F1.8 prime lens'. Also I want to do sports and car photography. Right now, I have the 17-55mm kit lens for my rebel xt, 50mm f1.8, 85mm f1.8 and 70-300 f-toslow. The lens I use the most is the kit lens, I find the 50mm gets me in to close after the crop factor on my rebel xt and 20d. I know its not the best lens, but it gets the job done, and the only negative I see from it really is color fringing on white shirts on occasion. Ive used the EF-s 17-55 f2.8 is, which I thought was ok, but rather heavy. I had a sore neck for a while after that. I would like to stay away from the ef-s series if I can though, I plan to get a 5d series camera down the road. The lens' Im considering for indoor portraits are: EF 16-35 F2.8L but thats rather pricey. EF 17-40 F4L is more my price range, but its also rather slow for indoor events. Plus no IS I believe. I recently discovered the Canon 17-200 F3.5-5.5 lens, and the price is great. Its rather slow, but I love the range. Does anyone know how the image quality for this lens is? Ive also heard about the Tamron 17-280mm F3.5 lens, I wonder how the quality is of that lens. I like doing nature photography when I have the time, but its more a hobby. Plus I want to do sports photography. I do have the Canon 70-300mm lens which isnt known for quality, but if you stay below the 200mm range, the quality isnt that bad. I noticed the other day the Canon 100-400 F4.5-5.6L IS lens, but again the price is a bit out of my range for the time being. Then today I noticed there is a Canon 100-300 lens that is a fraction of the cost. I am wondering how the image quality is of this as well. I know the extender things *not sure the proper name* that will allow me to multiply the lens by 1.4/2 degrade image quality slightly, and reduce the amount of light getting to the sensor, but one or two of those could make for a nice addition to the 100-300 lens. If my math is right, on a 1.6 crop body, it would similiate a 960mm lens, which could get me nice and close to the birds. : ) ** So my question for everone is, what are everyone's experience with the Canon 17-200 / tamron 17-270, and with the Canon 100-300 lens'. Also if anyone has any suggestions, please feel free to share. I do have two camera bodies, so one idea I had was to just use two primes for the indoor stuff. Perhaps buy the 20mm prime for one camera, and use the 50 on the other. I dont exactly trust the focusing on my 50mm 1.8 though, it doesnt always seem to be reliable. And for the car photography, I was thinking of either the EF-s 10-22 F3.5-4.5 but thats the ef-s series, or just get a Ef 14mm prime.