Facebook just launched a new Instant Personalization integration with travel planning site TripAdvisor. When users who are signed into Facebook visit the site, they’ll see a map of cities their friends have visited, a list of which cities have been visited by the most friends, and recent reviews and site activity by friends. Instant Personalization will automatically provide social recommendations, make it easy for users to make informed travel decisions with TripAdvisor.

People are accustomed to asking friends for travel suggestions and advice, making TripAdvisor a wise choice for the expansion of the Instant Personalization program. Without it, TripAdvisor can overwhelm users with its enormous database of travel reviews, and doesn’t provide a good entry point to exploring the site for those without a specific destination in mind. Since a person’s accommodation and travel activity preferences are often similar to their peers, reviews and destinations of friends are likely to be much more relevant than those of strangers.

The site culls data from TripAdvisor’s popular Cities I’ve Visited Facebook app to populate the visited cities map and “Your friends’ most popular destinations” list. The app became popular in the early days of Facebook applications, with users proudly displaying their map of previous travel destinations on the now deprecated profile box. Cities I’ve Visited already had over 1.8 million MAU by September of 2008, according to AppData.

By default, the map shows destinations from all of a user’s friends, but the travel histories of individual friends can be viewed by clicking on the photos to the right. In addition to the home page integrations, when users click through search results for cities, hotels, and more they’ll see which of their friends have visited that city.

Facebook launched the Instant Personalization program at this year’s f8 conference, and has since been striving to educate users on how the program only uses publicly available information, albeit without a user’s prior consent. After pausing the roll out of the program for a few months, Facebook began adding more sites, with Microsoft search engine Bing and web TV recommendations site Clicker being the latest to receive the integration. Facebook maintains that it will only provide Instant Personalization on trusted, high-quality, inherently social sites.

With the program now covering travel, food, TV, movies, music, reading, search, and collaboration, additional areas it could expand to include fashion or exercise, with fbFund winners Weardrobe and FriendFit as good candidates.