Well, how about just your name? The Japanese Planetary Society is going to be landing a probe on an asteroid in 2005 and returning with a sample of it. Before landing the probe will drop a ball with an aluminum foil sheet inside of it, etched with the names of spaceflight fanatics, on to the asteroid. The ball will help the probe land and will remain there when the probe leaves.
More info can be found here as well.
Actually it’s ISAS who is launching the satellite. The Japanese Planetary Society is just organizing the name collection. They did the same thing with their Mars probe. (Which, incidentally, is taking 4 extra years to get to Mars because they screwed up the course correction early in the flight.)
And just remember folks, if you want to avoid getting shot by the saucers, you can always hide behind the score at the top of the screen.