I've done it a few times, but always at the beginning of a tournament, (usually the first hand). The reason being, is that a number of years ago, someone asked Howard Lederer what he would do if he got aa in the first hand of a tournament. I'm not a Lederer fan, at all, but what he said made sense. At the start of a tournament, you've got a long game ahead of your. In lower buy-ins, the beginning of tournaments (especially the first hand), are all-in fests. If you're late to act pre-flop, and numerous others have gone all-in before you play, fold. Someone is going to get lucky, and beat you.
As the tournament progresses, and there are less players, things get more serious, and you'll still be in the game. Why risk going home early?
For me, it's tough to do, especially when you're looking at aa, or kk, but think about it....in a tournament, you're still going to get them again, at some point, and you can make much better use of them.
, maybe if there is a raise and a re-raise in front of me I would think to throw kk or maybe if there are multiple all-ins in front i will throw 
