That's funny. I implemented almost the exact same thing a few years ago, although mine is arguably more complete :)

https://github.com/pthatcher/pyrec

Here's my original post about it:

http://www.valuedlessons.com/2009/10/introducing-pyrec-cure-...

And here's my analysis of how much less memory it uses:

http://www.valuedlessons.com/2008/10/blog-post.html