Cool image of the Earth and Moon as seen from the HiRISE instrument aboard the Mars Reconnaissance Explorer in orbit around Mars. You can see a better version of the photo and read the whole story here.
This reminds me of the somewhat famous image taken by the Voyager I spacecraft as it was headed outward in the 70s.
At the Planetary Society I found a gallery of photos of the Earth taken only from Spacecraft. Check it out!