If you’ve ever lived in a big city, chances are you know the feeling: You’re walking around downtown with a few hours to spare at the end of the day, and you know that somewhere nearby—perhaps only a few blocks away—there’s a great bar or café that’s packed with interesting people. If it’s your hometown, you might even suspect that a few of your friends, or friends of your friends, are hanging out there. But there’s no easy way to find it, other than by roaming the streets and peering into windows.