Though none of us in this lifetime are likely to take actual tours of Mars (unless you’re part of the secret government that plans to move there when the end of the world comes—lucky jerks), Microsoft and NASA have a pretty good virtual tour going with the WorldWide Telescope software used to navigate the stars from the comfort of your computer chair.
According to Microsoft’s Dan Fay, who directed the project:
“We were able to take the imagery from NASA, combine it with their elevation models and lay them onto the surface of the globe of Mars. Now users of the WorldWide Telescope can zoom down and actually experience the surface-level detail of Mars. They can pan back and see the height of the craters or the depth of the canyons. The new Mars experience allows people to feel as though they’re actually there.”
The PC version of the WorldWide Telescope software can be downloaded from Microsoft. There’s also a web version that works on both PCs and Macs.