Twitter isn't the only option for travelers looking to connect online. A number of other sites promise deals, advice or just a chance to connect with like-minded vacationers. But not every site works for every traveler; one that caters to the backpacker crowd, for instance, might not be the best place to fish for five-star hotel recommendations.

Facebook

Number of users: 400 million active
Best for: Deals

Comment: Features 200 travel apps for everyone from cruisers to couchsurfers. Many travel companies also have their own pages, where they post photos, news and deals. Of course, because Facebook is one of the few such sites in our survey that allows companies as members, surfers should expect plenty of self-promotion.

Virtual Tourist

Number of users: 1 million registered
Best for: Questions

Comment: One of the oldest travel sites, its forums include posts on travel to all 7 continents, covering everything from best Arctic coats to Shanghai spas. Features a "Travel Guide" section that groups members and reviews by destination. Members also organize regular offline meet-ups for travelers looking to connect in the real world.

TravBuddy

Number of users: 1.6 million registered
Best for: Finding travel companions

Comment: Helps users find people with matching travel plans; say, someone to share the driving on a European road trip. Members can also create and comment on trip blogs, complete with photos and maps. One caveat for "seasoned" travelers: older members are definitely a minority on this youth-magnet site.

TripAdvisor

Number of users: 15 million registered
Best for: Complaints

Comment: Though better known for its (sometimes controversial) traveler reviews, the site does allow travelers to connect via forums and private messaging system. People with detailed questions on a certain locale can also contact certain uber-active members who the site has dubbed "destination experts."