The NTP, or network time protocol, Pool Project has reached the 1,000 servers milestone. It is still looking for more volunteers though.
NTP is a service that allows computers to keep themselves synchronized with international atomic clock time reference standards maintained by various parties, such as the U.K. National Physical Laboratory and the U.S. National Institute of Standards and Technology.
The NTP Pool Project was started in the wake of the massive proliferation of business and personal computers during the 1990's in order to address the rapidly increasing workloads on the reference time servers. The NTP pool shares out the worldwide time signal workload via a distributed hierarchy of time servers run by volunteer companies and individuals.
Due to the ever increasing number of computers in the world, the NTP Pool Project is on a constant lookout for even more volunteers willing to donate minimal computer cycles and bandwidth by running timeservers. The only real requirement here is a static IP address.
Hop over to the NTP Pool Project site if you are interested.