I feel I need to make a brief, general note on podium celebration and demeanor in the age of Facebook. Why does FB change things? Because before Facebook no one saw your podium celebration and no one cared. But if you're going to post your podium shot on FB, well, we probably still don't care, but you should at least put a little effort into getting it right.
In short, you only get to lift both hands in the air if you won. The end. Or if the stage begins to collapse and if you failed to lift your hands you (and other innocents) would be crushed otherwise. This is the first and most critical rule of podium celebration.
In lifting your arms, there should only be the slightest bend at the elbow, if any at all. If your biceps are parallel to the surface you're standing on then you're doing it wrong.
The winner may also only lift one arm if he or she chooses to.
If you finished second or third, you should lift one arm, but it must be the arm furthest away from the winner. Don't try to steal the winner's thunder. It's his day, not yours. You lost.
When you lift your hands, they should have something in them. Like a trophy or a bouquet of flowers. If you don't have anything to lift, your gesture should be as if you are celebrating, animated, the fingers unclenched and extended, as if waving (without actually waving) to an intimate friend from across a crowded room.
Also, if you finished second or third, it's sort of badass to look grumpy that you didn't win, but it shows better sportsmanship to look pleasant.
The winner should always smile and otherwise demonstrate the utmost in grace and charm (which includes being gracious, both to the promoter and to fellow competitors). Act like you're not unfamiliar with the top place on the podium, but that there's no place you'd rather be.
Podium celebration done right.