Social media platform – Dopplr is a two-year-old social network that compares your travel plans with those of friends you already have. This functionality is similar to TripIt (already mentioned).
InterNations.org is a global expat community for local experts.
Some start-ups are trying to create communities of travelers that can interact with each other in a Facebook-style format. My favorite of these is Gogobot. To take full advantage of this site, you need to be willing to be friendly with strangers. Because it is people you never met who may have the best advice about the hottest new restaurants in L.A., or the best way to get to downtown from the airport during a transit strike in Paris. The one downside is that Gogbot’s community is still small.
A site with a much bigger group of travelers—half-a-million, give or take–is IgoUgo, a community that’s overseen by Travelocity. This past fall, it dded new social tools, such as an “I’ve Been Here” feature and a “Get Ideas from Other Travelers” button, which together can help you to find like-minded travelers and learn about their tips, as well as share your own advice.
Globetrooper Helps you connect with like-minded people (usually complete strangers) to plan experiences abroad. About 1,400 people, mostly Aussies, have “liked” the year-old service on Facebook so far.
Vacation Relation This is for Spring Breakers only. Teaming up with StudentCity shortly, this site will let young people find out if their far-flung friends are going to be at a warm-weather destination at the same time as they are.
Travel with Spirit Want to do some faith-based traveling with a fellow Christian? Post an ad in the forums of this site, which also spotlights nifty package trips and suggests destination ideas.