I came up with something a couple of weeks ago; I call it Pure Zero, and it's essentially kicking as much butt as you possibly can with only a level 0 character. We have a group, now, as it started getting some interest.
PZ is all about the challenge, and bringing back the appreciation for low level gear and maps. PZ also forces you to work better as a team, and in some cases, more than the regular side of the game. After a while of playing as PZ, you will likely find yourself appreciating your high level characters a LOT more.
If you're interested in trying it out, go for it! If you'd like to play with other PZers, chat about it, and whatever else, then check out our new group: