I would recommend adding it to your signature at other similar sites. Some sites have policies on posting similar sites, but they do not much mind you advertising it in your signature as long as it's tasteful. I would recommend that you also make up business cards with the info and pass them out to people on the street, or put them on boards in markets. Target the type of audience you wish to attract. If it's a music forum, stand outside of a concert and hand stuff out, if it's a tech forum, see if your local BestBuy has a board in their store. Good Luck!
EP, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS