Mars24 is a really cool downloadable tool for all you astronomy fanboys and girls out there. It displays the Mars sunclock, a graphical representation of Mars and a readout of the time in 24-hour format, amongst many other cool things.
You can also use the program to display a panoramic view of where the Mars Phoenix is currently located, and can adjust it to see north, south, east and west viewpoints. I like the feature that allows you to see the local time for Earthlings and Martians.
I’ll just hook this into my Tom Tom and off I go!