Fire Eagle is the secure and stylish way to share your location with sites and services online while giving you unprecedented control over your data and privacy. Fire Eagle shares your location information with services and applications that you choose. This location information is obtained from the web or your mobile device.
It launched privately on March 5, 2008 with very few user-facing features—allowing users to manually update their location—and a range of APIs allowing app developers to update or access that location programmatically.
Fire Eagle is currently invitation-only : http://fireeagle.yahoo.net/