Managing Multiple Versions of Python with pyenv

I have been recently working on a project that needed to be tested on multiple versions of Python.  I found pyenv to be invaluable:

https://github.com/yyuu/pyenv

This project was apparently forked rbenv and ruby-build and works about the same.

I also found this article useful:

http://dtucker.co.uk/hack/installing-pyenv-on-mac-osx.html