Dopplr, the latest social net to focus on travel tips, has received an undisclosed amount of funding from a group of international investors including Martin Varsavsky, Joichi Ito, The Accelerator Group led by Saul Klein (also of Index Ventures) and Reid Hoffman, founder of business social net LinkedIn. Dopplr was founded by Lisa Sounio, who now serves as CEO; Matt Biddulph, chief technology officer; Matt Jones, design director; and Dan Gillmor, the former columnist for the San Jose Mercury News and citizen media blogger who’s identified as “founding traveler.” Additionally, Marko Ahtisaari is listed as a founding investor.

The Helsinki-based Dopplr operates via an invitation system, whereby members share future travel plans with others who are part of their individual group. It’s aimed at frequent world travelers. It also offers alerts to friends in other cities about when a user is visiting their city and where the person will be staying. Dopplr doesn’t say how many users it has; it only says that travelers have shared over 70 million miles of trips to roughly 2,000 cities. Release