Never mind the obvious benefit of taking your brain out for a vigorous stroll. The real beauty of bridge is the other players.
When I mention my passion for the world's best card game to the uninitiated, the subject of little old ladies always arises. Certainly, that contingent is represented. Crafty little old ladies. Cunning. But the truth is, the bridge subculture is diverse: Bums, brainiacs, and billionaires (ask Bill Gates and Warren Buffett what they do for kicks) fill up local bridge clubs, national tournaments, and online bridge parlors. Learning to play bridge will allow you to match wits and witticisms with an array of folks whose only other commonality is that they tend to be pretty clever.
You don't need to be a genius to become good at the game, though. Judgment and the ability to focus are greater assets than sheer mental muscle, and both develop with experience. The basics of bridge can be learned in an afternoon. It's a trick-taking game, like spades and hearts, but with a few extra layers that make it much more interesting. Cheap or free lessons are available online and at many community colleges and bridge clubs. The American Contract Bridge League will point you in the right direction. Many novices prefer to hone their skills with computer programs such as Bridge Baron ($65).
All it takes is three friends and a pack of cards to play a standard game of bridge. But for the real thrill of competition, try duplicate bridge—in which you and a partner rack up points for outsmarting other teams playing the same cards (hence, "duplicate"). Some online bridge parlors, such as Bridge Base Online or OKBridge have free games, but these are tepid substitutes for live play. With about 3,200 bridge clubs in North America, the ACBL can help find one near you. Clubs typically charge a small fee (generally about $5) for three hours of play, and that often includes snacks. Clubs are eager for new members and will usually help you find a partner. There are thousands more clubs worldwide. You'll no doubt find a warm welcome at every one.