I've done the same sort of thing some time ago. I got a friend to hold the camera.
The room wasn't completely dark, so you can see a bit of me and the room. Also, the light I used (flashlight in my mobile) didn't give constant light, which can give you some cool effects, depending on the speed you're moving it...
here are two examples, not the very best, but I havent got them all online.
This was my self portrait
