I do it a lot when in a loosing position on live chess, simply because I don't find it interesting to get better at fighting loosing battles. The only chance you have it mostly is if the opponent makes a random bad mistake - this however makes it luck based and therefore uninteresting to me in most of my moods.
Maybe when I feel that it makes sense to improve that part of the game I'd stop resigning so hastily.
Can I ask a simple question, by a simple boy like me... why oh why do some players resign when a) a game is getting good (for me, I hasten to add) b) the opposition loose there Queen... I never resign but fight to the death, its unfair on the other player who perhaps got a great plan and would like to see it through... plus I may force a draw! ;o) but seriosly I have had a lot of players resign on me... Why?