I'm going to start working on this again, because it's a really good way to learn things about oneself and play out certain future scenarios so you can know what to do in advance. There are a multitude of other benefits, if you do it right. Some people even use it to play out sexual fantasies. Whatever you wanna do, I guess.
For the unfamiliar, lucid dreaming is nothing but dreaming while knowing you are dreaming, hence the "lucid". Thus, if it happens a lot, you can learn to control your dream completely and play out any scenario you want to. Most people I've talked to have experienced this at some point in their lives, but with practice it can be done with frequency and greater control.
I tried doing this a few years ago, but then got distracted by other things. I've wanted to work on it ever since, but never really got around to it. I just found the same exact FAQ/"guide" to lucid dreaming that I was using years ago, and it seems like a really good one. If you're interested, go take a look.
If I reach any success, I'll post. I have a few odd dreamachine experiences I haven't put up yet...
Oh, and over at Erowid there's a good section on dreaming in general (and a mini-section on lucid dreaming). I haven't filtered through it yet, but for the interested: click