pip installs Python packages. It knows about PyPI, various source control systems, and even local setup.py files. For example, to install Tornado HEAD from GitHub:

$ sudo pip install -e git+https://github.com/facebook/tornado.git#egg=Tornado

To install Tornado 1.1 from PyPI:

$ sudo pip install Tornado

To install Tornado from a local clone of the source:

$ cd tornado
$ sudo pip install -e .

This last one really just symlinks the source folder into site-packages like the distutils develop option.

Uninstall is easy too and seems to be based on simple pattern matching.

$ sudo pip uninstall tornado