First of I'm not made of money so I'm trying to keep this cheap.I just bought a 40D, had a 20D a while ago but sold most of my glass with it so I'm looking again.I just bought a 17-85IS as a walkaround lens, it's great at 85mm, quite sharp but at 17mm it's weaker and has a lot of fringing, but I am still able to return it.I take mainly landscape and macroish shots, I'm a nature photographer and had though of this kit.My main lens (also most expensive)would be the 24-105 F4L IS because I figured this lens would take 80% of my photos, so I would go for a good one and I love IS.Then for wide angle I would get the Sigma 10-20, since that 4mm between the two lenses can be done by foot zooming.I also like to take some telephoto shots but it's not my main interest so I though about the 70-300IS as it seems to get good reviews and has a good range with IS (and isn't to expensive)A bonus I see is if I ever go FF, which I would love to if it gets a bit cheaper 2 of the lenses would still work, and then I could just sell the sigma for the 17-40LPlease if you have any recommendations let me know, is the 24-105 an excelent lens, I assume so since it's an L and if I get some extension tubes could it be used as a pseudo-macro lens.Thanks so much!!