I figured I'd start this one here. So far I have found three excellent ones which are pretty easy:
1.) Wear sunglasses. Seriously, food looks a lot less appetizing when it is all dull and desaturated (you see less color when it is darker.) Indoor environments will make the latter more noticeable. Your rods do not see color ;)
2.) Eat 100% dark chocolate. It is bitter and suppresses my taste buds at least enough to be noticeable.
3.) Drink a non-flavored fiber mix in a cup of warm water. This will totally turn off your taste buds and kill any appetite you might have, or at least it does with my fiber mix. Bonus points for squirting a little bit of lemon juice/extract in with it. The sourness works well.
What do you guys and girls have to offer?