Good advice above! Many stores that specialize in (or have a substantive section of) RPG's, also have cork-boards or other forms of "players seeking groups" and "groups seeking players" sign-up.
I've also discovered that Meetup (meetup.com) often has good leads. It's a website oriented towards creating in-person "meetups" of folks with similar interests. Photography, programming, bird-watching, hiking... RPG's.
Honestly, it's not the easiest place to find your way into... more than once, I've wondered at how hard it can be to FIND the content you're looking for. But it's usually there...
Many colleges, both JrCollege and 4year+ institutions, have gaming-clubs (societies, "guilds," what-have-you's); some encourage community outreach/involvement, some simply don't care -- show up and ask to participate! A few, I've heard, have been forced to be hard-nosed about "students only," but I've never met one in-person.