NASA's Intrepid Mars Rover

The tiny mobile robot named Opportunity is NASA's little engine that just keeps on kicking interplanetary exploration ass. This robot has been chugging away across the Martian landscape since it landed in January of 2004, and is fully-functional after over 30 months in the Martian environment. That is quite an accomplishment considering that its original mission was slated to last a mere three months.

Opportunity is now set to reach Victoria Crater, a potential treasure trove of science data. Go! Go Opportunity! Go!

Check out these links for more details.
A full article on Universe Today
Original NASA Release
NASA Rover Site