I bought a Canon 30D in November and opted for the body only. The walk around lens I chose was the Canon EF-S 17-85mm f/4-5.6 Image Stabilized USM. It is a great lens, but I'm not certain if I would make the same choice now that I know more. Let me emphasize, it is a great walk around lens. But at f4 it is a little slow. And at $485 it is a little pricey.
At the same time I bought my girlfriend a Rebel XT with the kit lens. The kit lens is fine for snap shots. Friends and family, capturing moments kind of thing. But the first time you see a side by side comparison of a tack sharp image from a fine lens next to it, disappointment really sets in.
I tryed to help you more by reading up on some popular lens choices, but I found that if you google "What is the best walk around lens for Canon DSLR" you will get lots of good information and you won't need me to give it to you second hand. Then once you've narrowed down your choices, ask for personal experiances from this group. Some are very knowledgable.
Hope I helped.
Mike