If you want to shoot landscapes and buildings I think the kit lense should be okay. Animals may be an entirely different beast (only a small pun intended). Depending on how shy these creatures are, and how close you manage to sneak up on them, you may need a dedicated macro lense for those shots. But - from my very, very limited experience - there simply isn't a single lense that will do everything for you. If you hope for the "egg-laying wooly pig", as a German expression goes, you may never find it. If you have a chance to rent a lense for a few days I would suggest you check out something in the 28-135mm range, to see if that will serve you well. It's what I use, and the only thing I miss compared to the kit lense of the 400D is the slightly wider wide-angle setting. And if the price is important to you, try ebay or similar sites, once you have decided on a lense. The Canon 28-135/3.5-5.6 IS USM I now use on my 400D I bought used, but it works perfectly well and I got it for quite a bit less than a new one would have cost. Even if you want to support your local store, check around first, then mention to the local guy that you could get item X for $Y online and see if they don't offer you something better than they offer the average customer.