Yup. Depersonalisation disorder. It's crazy. I have episodes where I just have out of body experiences, usually during times of change, like an unfamiliar situation. It's usually not good, because I generally can't focus on anything, speak in a very different way, and speak a lot less, this usually occurs at parties, when it's raining, or late at night when I would usually be in bed.
It can be good, sometimes, however. An example of this is when I am doing a performance (I do a lot of acting/drama, representing my school *brushes shoulder*). These episodes come about during most performances, and I just simply do the performance, totally seamlessly, without having to think consciously of anything. So this is really strange because I find myself thinking of errands I have to run, or even something like video games, and the performance still goes just fine. The words just come out of my mouth, and even though I'm thinking of something different, everything just fits together.
That is really the only benefit of a depersonalisation disorder, and the disadvantages far outweigh the advantages, so I'd definitely rather not have it.
Oh, and I've also got an anxiety disorder, but that's not really worth mentioning, because a lot of (if not most) people on WP have one.