This is a bit off-topic, but where else to put it?
Last year, terraforming Mars was the stuff of high science fiction. This year? A recent image taken in June 2007 by the Mars Reconnaissance Orbiter (MRO) of Victoria Crater, where the Opportunity rover has been rooting around, clearly shows the rover’s extensive tracks as it explores the edge of the crater:
MRO’s photographic imagery is taken by the HiRISE camera, which has a resolution of better than 1 meter per pixel. It may be a narrow path for Opportunity, but a giant leap for mankind’s impact on Mars:-)
BTW, lots more really impressive high resolution imagery taken by HiRISE is available on their very slick redesigned site. How slick? One of their download options for new imagery wallpapers is for the iPhone.