Send Your Name to Mars
I found this via The Planetary Society:
As an interesting public outreach the good people at NASA will allow anyone, adult or child, to submit their name for inclusion on one of several DVDs which will be taken to Mars via one of the 2003 rover missions and photographed on the surface. You can submit your name here, but hurry up, you've only got two days left!
Yes, they did this before, for the Polar Lander :(. Please let's all keep our fingers crossed for this one.