What would you say if you had the chance to leave a message for someone to read 50.000 years from now?
The KEO satellite is a satellite space time capsule which will be launched in the end of year 2007 or 2008 carrying messages from the citizens of present Earth to earthlings 50,000 years from now, when the satellite orbiting Earth will return.
You can leave your message, here. The deadline is on December 31, 2006.
More information about KEO, here.