The next Mars rover is due to be launched sometime in 2011. You can get your name or the names of your loved ones added to a microchip that will be on the Mars Science Laboratory Rover before it is launched.
http://marsprogram.jpl.nasa.gov/msl/participate/sendyourname/Check out this link for more information about the mission:
http://marsprogram.jpl.nasa.gov/msl/