This is regarding the editing for this photo (because someone on Flickr asked):
Okay. First I took the photo of me 'sleeping' using the self-timer.
The camera needs to be in exactly the same place for all of the photos. It would be extremely helpful if you owned a tripod. I do not. I had to balance my camera on an easel.
Then I sat on a stool on top of my bed and took this part of the photo:
Then stood up and took the rest of them.
I use a free editing software called GIMP to edit my photos. I put the 'sleeping' photo as my base image. Then I put the first of the other images of me on top of it. Then I used the eraser tool at 100% opacity to erase the stool and my legs and most of the background so you can see the base image of me as well. Once I'd done that and the photos looked like just one photo, I used the eraser tool again, but at about 50% opacity and went over the top photo of me.
After that you can anchor the layer down and do the same with each of the photos separately.
After that, I used the equalise tool to adjust the colours and brightness and things.