You can send a personal message into an outerspace timecapsule that
will be launched by an Ariane 5 rocket into an orbit 1,800 km high, an altitude that will bring it back to Earth in 500 centuries, the same amount of time that has elapsed since early humans started to draw in cavern walls.
Get your kids and your grandparents to write notes:
Every person is invited to write a message addressed to the future inhabitants—the deadline is December 31, 2009. Messages can be posted via the project's website, or sent by postal mail. The organizers encourage everybody to gather messages from children, senior citizens and the illiterate so that every culture and demographic on Earth is represented. The satellite has enough capacity to carry a four-page message from each of the more than six billion inhabitants on the planet. Once the satellite is launched, the messages (with personal names removed) will be made freely available on the web.
I think I will either publish a Conan the Barbarian story, or a message from Kirk: