My pool of 20-odd gamers that I know, I all met through various connections.
My first regular group I met through high school - I saw a guy reading the 1E player's handbook in Typing class, and we struck up a conversation. Soon, I was introduced to about 5 friends who gamed. Most of them moved on from town a year or two later, but their younger brothers/sisters/nephews too up where they left off, and I gamed for several years more. (The weird thing about those five friends was they all had family about two years younger, who they introduced to gaming.)
After a dry spell of about two years, I met a person through work, who is now a dear and close friend. He introduced me to friends of his, about 6 strong, and we gamed for several years. Later on, after a few of the "old guard" moved back into town, and I got them re-interested, and gamed with various combinations of people over the next three years.
Finally, we met and introduced various others from work, from common interests, etc. - Culminating in knowing about 20-odd people who know each other, who keep in touch, and who game on a regular basis.
MY RECOMMENDATIONS:
Gaming stores
The "Gamers seeking Gamers" forum on ENWorld
Aquaintences from work with whom you share common interests.
It's also good to know that whoever you join could also share other interests with you besides gaming - it's good to meet through gaming, but it's ever so much easier to keep gaming regularly if the people you game with are friends.