Golf-specific exercises don't have to be as strenuous as other workouts, so we're going to start with an "easy" one. (Heh heh heh!)
I call this the balance beam.
Take your normal golf setup (no club) with your knees flexed and your spine tilted forward. Now, with your knees still flexed, I want you to stand on one foot. Shift your weight to the leg that will support your weight -- keep your knee flexed! -- and lift the other foot until you can rest that ankle against the side of your support knee. You can keep your arms close to your body or hold them out to the sides, I don't care; do whichever helps you keep your balance. Got that? It shouldn't be too hard...
Now, while you stand in that position, I want you to slowly turn your shoulders as far into your backswing position as you can, hold it a second, then turn as far as you can in the other direction into your followthrough, and return to your start position... all while standing on one foot with the other ankle held against your supporting knee. Simple, huh?
Do that ten times, then switch to the other leg and repeat.
This little gem will not only improve your balance, but it will also improve your hip and back flexibility. Hip flexibility gets overlooked by a lot of people, but it's important if you want to avoid back problems.
Got it? Good. You go work on that, I'm going back to watch the Olympics. The half-pipe guys are on -- GO SHAUN!