Isahrai Azaria is heading to Austin, Texas, in February, and thanks to Facebook, she already has 40 acquaintances, an invitation to go water tubing, and a line on the best vegetarian lunch place in town. “It's been unbelievable,” said Azaria, a singer who lives in San Francisco. “It was just a quick post on Facebook, but one of my Facebook friends is friends with some people in Austin,” and those friends sent her tips on everything from yoga studios to local bus service. Social media is changing the way people travel. It's replacing recommendations from experts and strangers with a targeted selection of information from acquaintances and their networks. Travelers have used the Internet for years to find hotels, restaurants and other attractions. Some Web sites offer recommendations from guidebook writers, critics and other experts, while others — like TripAdvisor.com, Yelp and Chowhound — offer feedback from individuals about their personal experiences. But credibility can be an issue. A good review could be written by the business owners themselves or their friends, while bad reviews could come from their competitors. A destination Web site might only list businesses that pay to be featured. In contrast, a recommendation from a Facebook connection or your Twitter feed may feel more trustworthy and less random than something you stumble across on a Web site — even when the tweet or Facebook message is from someone you don't know. “I see my social media network as a big focus group, a big travel guide,” said Jessica Flynn, who owns Red Sky Public Relations in Boise. “I don't know all the people directly who I follow on Twitter, but I just find them interesting.” Last summer, Flynn let it be known on Twitter and Facebook that she and her friend were headed to Vancouver Island in British Columbia, Canada. She heard back from the owners of cheese shops and bed-and-breakfasts. “It is commercial, in a way, but it also gives me a connection that I would never have had,” said Flynn. “I wrote back, ‘I'll be 30 miles south of you. What do you know about that area?' And then they responded and gave me something.” Airlines, hotel chains, tourism agencies and companies like Orbitz also use Facebook to keep fans up-to-date on specials and deals. Facebook applications like Dopplr let users share travel plans and add reviews. Outside of Facebook, trip-sharing Web sites such as Everlater provide a way for travelers to post their stories and photos. Twitter has become a medium for travel-related businesses to provide quick messages about upcoming events, promotions, even weather conditions. It's also a way for these entities to identify regular customers and reward them with discounts. Other travel businesses use Twitter to build relationships with customers and promote visitor satisfaction by answering individual queries through Twitter with on-the-spot advice. A Web site called Twisitor Center lists hundreds of local tourism authorities around the world that tweet: http://twisitorcenter.com/. Tweets are especially handy if you're walking around outside looking for a good breakfast place.