Google Mars is up with some amazing pictures of the Martian landscape from NASA. The pictures are available in three ways: an ‘elevation’ topographic model, a visual satellite image, or an infrared satellite image. It is the same interface as Google Maps and includes indexed maps of the highlights, like mountains, canyons, and craters.
If you know the name of a particular landmark, there’s the ubiquitous search box to help you along. I tried searching for Taco Bell and the post office, but, alas, nothing came up. Maybe in version 2.