I'd look at a Nikon D60 or similar (i think they replaced it with the d3000?) with the kit lens + a 55-200 VR. You should be able to set yourself up with that for under $1,000. Throw in a 30 or 35mm fast prime (f/1.4 or f/1.8) into the mix for low light and you have a solid setup. (I have my old D60, 2 batteries, 18-55 kit lens and 55-200 lens if you are interested in it... also have a Nikon 18-200mm lens I need to get rid of... although I was not too happy with the image quality of the 18-200).
I have been doing a lot of travel photography and used that setup extensively while I learned the basics.
I wanted easier manual control so I upgraded to a D300s (would have gone with the D90 but it has no weather proofing... I'd hate to be in a small drizzle and ruin the body on vacation).
The setup I run when traveling:
D300s
Nikon 16-85mm VR (general walkaround lens)
Nikon 70-300mm VR
Sigma 10-20mm (for wide landscapes, etc)
Sigma 30mm f/1.4 (low light)
The D300s also has dual memory card slots so I can write images to both cards (I am paranoid about having a memory card go bad on me and losing a good batch of photos).
Another high end option would be the full framed D700 which is an amazing camera for High ISO / low light, but I could not justify the additional weight of quality FX glass for a travel setup. I am able to fit all my camera gear + laptop in a relatively small backpack.
Some pics with the D300 setup (I am still learning...)
16-85mm (town of Gefyra shot from Monemvasia, Greece)
16-85mm 15s exposure
70-300mm (Skansen in Stockholm)