These lens suggestions are always difficult. I would take a differnet approach then the two before me. You have a lens that covers 17-85mm, it's not a high-end lens, but it will make some nice pictures. What I would do, is looking for a lens in another range.


For the wedding I would even consider a external flash-unit, especially when the wedding is indoors, or lasts into the evening. Here you can go with the Canon EX430 or EX580 (depending on your budget), or if money isan important point, you could also buy a Metz (mecablitz 48) it has more power than the EX430 for about the same price, or a Nissin Di622, which costs almost half of theCanon with the same power(LZ44). Another possibility would be a 70-200 f4 or f2.8, these ar nice lenses, the question is, how much you will really use them, and is it worth the money.


For travelling I would suggest a wide angle. I will you go to a lot of beautyful place, but as soon as you look through the viewfinder, most of the beauty is gone, because 17mm is not wide enough. There are differnet options for wide angles; there is the EF-S 10-22 the Tokina 11-16 f2.8 or 12-24 f4, the Sigma 10-22mm or 12-24mm and the Tamron 11-18mm. All of them, except the Sigma 12-24mm are APS-C only (you cannot use this lenses anymore ifyou upgrade to full frame). For the review of the lenses you go here: http://www.photozone.de/canon-eos. I own the Canon 10-22mm, and I'm very happy with it. It gives beautyful landscabe shots, but is also very nice to take indoor shots of buildings.


I personaly would go for the wide angle, and later I would buy the 70-200 (or something similar like a 50-150mm), or if you don't really miss the telezoom, you could also upgrade your kit-lens to a 18-50 f2.8 or a 17-70 f2.8-4.5.