Now, a number of start-ups, such as Planely and Satisfly, are taking the concept to another level by helping travelers meet not only online, but in person. Call it the of travel. "It's about real connection," says Asaf Engel, co-founder of IMGuest, a social-networking site for business travelers staying at hotels. "It's about being engaged. We push people to get along and meet up." Airlines such as Delta have already been experimenting with social media by selling tickets on Facebook. Now, some carriers are trying to tap more aggressively into customers' social circles. Get the full story at USA Today