i found this:
http://blog.liw.fi/posts/vmdebootstrap-2/
I got no clue if it is a good idea or not. At least not yet.
Perhaps some of you are interested.
If you go to https://gitorious.org/vmdebootstrap
and look at the source-code, it is in python and its not that much of code.
I mainly store it here, instead of a bookmark, but it ~might~ be someone is interested...