It's basicly a mod that let's you convert a 3d-model that you have made in some software to a model vinsisting of blocks (such as Minecraft is). This new block-model can then be implemented in any of your Minecraft saves by the use of MCedit.
I found this idea very interesting so I had to try it out, and here is what I menaged to make just now.
I have not made the hand itself, I just took it for a tutorial and trial purpose. I had to work a bit with the cmd-window since I am not used t working with it. But in the end I menaged to get it right. The only thing I could figure out how to do is to rotate the hand so that the fingers are pointing upwards. When I tried to rotate it round what I thought to be the z-axis the whole thing just became a stright line, with no dimensions at all... how wierd isn't that?
EDIT: I think the problem with the line was that I tried to move the hand to a negative referense plane when rotating around the z-axis. If I rotated 180 degrees around the x-axis it worked perfectly to get the hand standing. I won't make a picture of that though, just trust me, it's there!