Coming from someone who's had his house vandalized (when I was younger,) I cannot for a moment support things like TP or driving into people's yards, etc. Not being offensive - it's just something that high school kids do, and I think just about all of us are older than that.
I myself still have my lights up, but they're unplugged and I do not turn them on. I've been out of town every weekend since beFORE Christmas, and haven't had time to take them down. I do however have Christmas lights up in my living room, running from corner to corner around the room - I love turning them on when I'm up late, or watching a movie with the wife, or when you just want some color to enjoy. They were hung shortly after we moved into the apartment (In March 2006,) and have been up ever since. I believe that the Christmas spirit SHOULD live the year-round, though few of us tender the spirit in our hearts - myself included.
However as far as outdoor lighting for the season, I definitely leave them up through New Years, and usually take them down the first weekend after January 1st. Same goes for the tree and such. However if I had a place large enough for an indoor tree to remain decorated, I would. I love Christmas, Christmas lights, and Christmas trees (and Christmas presents!) Nothing else brings me such joy during the year.
Jeff