Each night as I prepare dinner, I put out a bowl of baby carrots and sliced apple on the counter top. Some nights I might vary it by putting out some sweet, juicy grapes or some chopped broccoli. As I prepare dinner and the smells of cooking food make my stomach growl, I pick at my bowl of fruit and veggies.
The good thing about this strategy is that it usually means I don't overeat: I sit down to my meal having filled up a little on good and healthy stuff.
If you think that's not enough to curb those near-mealtime munchies, you can always chew gum while you cook. This makes it rather harder to pick and nibble.

