dopplr
(The Dopplr “beta” service is open by invitation only.)
Dopplr is an online service for frequent travellers. It lets you share your future travel plans with a group of trusted fellow travellers whom you have chosen. It also reminds you of friends and colleagues who live in the cities you’re planning to visit.
update 1/1/2008:
dopplr has been released.
☍ 30.03.2007