I just wanted list a few projects that exist and pertain to this question.
LAGEOS - A series of scientific research satellites which use lasers to measure the planet's shape. LAGEOS-1 is predicted to reenter the atmosphere in 8.4 million years and contains a plaque designed for review by future humanity. It was launched in May of 1974.
Memory of Mankind project - Has an estimated lifespan of 100,000 years. They are storing information on inscribed stone tablets and storing them in a salt mine in Austria.
Rosetta Project - It's goal is to preserve around 13,000 pages of information in each of 1,500 languages on a disk made of nickel. The disk can be read with a microscope and is contained within a 4 inch spherical container. One of these disks is on the Rosetta spacecraft that was launched in March of 2004; although it's mission ends in 2015.
KEO space time capsule - Has experienced several delays and has not been launched yet. Estimated to launch in 2015. It's purpose is to reenter the Earth's atmosphere in 50,000 years. It will apparently carry around 24 billion pages of messages on a DVD with symbolic instructions for how to build a reader. It will also contain a drop of human blood and samples of air, sea water and earth encased in diamond.