The Long Now Clock. They're actually building it.

*Really. They're not kidding.

http://www.10000yearclock.net/learnmore.html

"This is a big project in multiple ways, and there are many partners who are helping make it a reality. Here's a list of some of the organizations that are key to the project.

"Applied Minds, Inc. is Danny Hillis' company that leads the design of the Clock;

"The Long Now Foundation is a non-profit foundation that was established to foster long-term thinking and focuses a tremendous amount of its energy on the Clock. Special thanks here most especially to
Alexander Rose and Stewart Brand;

"Penguin Automated Systems, Inc. has provided guidance on the underground site development;

"Swaggart Brothers, Inc. continues to lead the construction aspects of the project;

"Seattle Solstice are masters of custom-design stone objects and have developed a saw that will cut the spiral staircase out of stone in the Clock chamber;

"Machinists, Inc. are metal fabrication specialists who have delivered many of the Clock parts...."

lm_10

"The Clock's chime generator creates a different bell ringing sequence each day for 10,000 years...."