My name is among those listed and carried on NASA's Martian rover, Curiosity. I signed up with NASA on its Mission Participation page several years ago. NASA sent me by email a participation certificate which I posted on my photo page on a site called Communities.com. NASA's Mars Science Laboratory mission is preparing to set down a large, mobile laboratory - the rover Curiosity - on August 6, 2012.
There are 529,386 US names and at world wide total of 1,246,445 names cared on the the Martian Rover, Curiosity. Here is the NASA link to see the world wide totals by nation: Mars Science Laboratory: World Participation Map
BTW, my name was also on a compact disc carried on the impactor spacecraft that crashed on Tempel 1 on the NASA mission, "Deep Impact Discovery Mission to Comet Tempel 1". My name was on also NASA's Dawn spacecraft which investigated the asteroid belt.
Forget about taking pride in being an international traveler. Try being a spaced traveler like me. I am a bit weary of all this travel so you might say that I am "spaced out".