How Long Should You Keep Your Christmas Decorations Up?

This morning I woke up and started packing away the majority of my Christmas decorations. I usually wait until after New Years but I'm heading out of town for a few days. The only thing I left was my Christmas tree because I'm just not ready to say goodbye to it yet. I also left my lights outside up but when I go out of town I will probably unplug them along with the timer so I don't waste electricity.

I know that some people pack things up the day after Christmas and some others leave decorations up for weeks after. Then, we have a few stragglers that tend to leave their Christmas lights up until May! When do you pack away your Christmas decorations?