Apparently where you travel may affect who you travel with in the future, and two new digital tools aim to connect people based on their travel itineraries.

Apparently where you travel may affect who you travel with in the future.

This August, researchers at Cambridge University published a paper suggesting that the places people travel to help predict which strangers they'll become friends with later. Researchers studied four months of social activity on the location-based mobile application Gowalla, and predicted about a third of the new social connections made during that period, just by noting which users "checked in" to the same places.

Despite this tendency to become friends with travellers who visit the same places as you, few websites or mobile apps make it easy to connect with people who have similar travel tastes.

New site Ajungo aims to fill the gap in the market by allowing travellers to connect with locals before their trip, in the hopes of meeting up with one during their vacation. Ajungo is free and easy to use. Just sign up for an account, answer some questions about yourself, your travel interests and upcoming itineraries, and connect your profile to one or more of the major social networks, such as Facebook, LinkedIn and Twitter. Ajungo then helps you introduce yourself to locals, based on shared interests and travel patterns.

The service, while promising, has yet to leap a common start-up hurdle. Since its debut in late September, the site claims to have facilitated more than 100,000 interactions, but based on the number of member profiles currently on the site, Ajungo hasn't attracted enough users yet to provide a pool with promising chances at social connection.

Triptrotting, a year-old, US-based social networking site that targets students and professionals between 18 to 35 years old, is the only website that comes close to helping travel hobbyists meet other travel hobbyists. To verify that its users belong to a university, or a major company or non-profit, the site requests an official e-mail address affiliated with the institution, such as "carnegie.org". Triptrotting then uses an algorithm to suggest locals in a user's upcoming vacation destination that he or she may have things in common with, so young teachers would have a chance to be introduced to other young teachers while travelling.

Because making friends with a stranger can be awkward, Triptrotting encourages users to engage in specific activities, such as having a host take a visitor to their favourite local restaurant, little-known art gallery or hot new nightclub. Hosts may ask for a tip in advance to cover any costs and to discourage visitors from flaking out. Triptrotting holds the tip (usually up to about $30) in escrow until the traveller signs in, agrees he or she had a good experience and wants to release the tip to the host.

For now, no social-networking service recommends potential travel-loving friends to members based on shared travel patterns. But the researchers at Cambridge suggest that it is possible, if a site based its friend recommendations on users that have “checked in” to similar places.

For example, For the past year, Facebook has invited users to "check-in" to places using the geo-location services of their mobile devices, but it still recommends potential friends based on the "friends-of-friends" a user already has, not based on the travel histories of potential friends.

Meanwhile, Foursquare -- the largest location-based service, with more than one million users -- has also yet to tap into its databases of "check in" histories to recommend friends to its users. Today, when a Foursquare member checks in to a location, they only see "others here" with non-identifying avatars and primarily first names. There is no additional information about the person's interests or past travel histories.

Rival location app Gowalla doesn't recommend potential friends based on check-in histories either. But in late September, it launched a redesign of its app to help travellers have more a social experience at their destinations. The app debuted more than 60 guides to major cities worldwide that are based on the recommendations of its users. Users can also tell "stories" about their visits to particular places and tagg the Gowalla profiles of friends who joined them.

So what are the second-best options for a site to make travel friends? While tools like Triptrotting and Ajungo are promising, you don't need third-party vetting or a fancy algorithm if you're willing to make the connections yourself. A few travel-themed social networking sites bring like-minded travellers together for several reasons. Some help travellers connect with locals to find homestays (such as Couch Surfing and Tripping), find local intelligence on hot restaurants and clubs (such as Gogobot, Travellerspoint and Internations), or find dates (WAYN, aka "Where Are You Now?").

Each site tends to attract a particular type of traveller, so if you visit one and don't find it to your liking, you should try another site that might better suit your style. Couch Surfing has more than two million members, and member identities are vetted by a third-party verification service. While it has members of all ages, frequent users tend to be in their early twenties. Tripping is similar to Couch Surfing, but places more of an emphasis on local cultural immersion by a more mature crowd. Gogobot has a membership base heavily drawn from North America, which limits the pool of people to meet.  Travellerspoint has a broad base of Europeans, and Internations is strongest outside of the world's 10 wealthiest nations.

What's your favourite social-networking site for travel? Let us know by posting a comment on our Facebook page or by contacting us via Twitter.

Sean O'Neill is travel tech columnist for BBC Travel