How do I manage third-party Python libraries with Google App Engine? (virtualenv? pip?)

What's the best strategy for managing third-party Python libraries with Google App Engine? Say I want to use Flask, a webapp framework. A blog entry says to do this, which doesn't seem right: $ cd /tmp/ $ wget http://pypi.python.org/packages/source/F/Flask/Flask-0.6.1.tar.gz $ tar zxf Flask-0.6.1.tar.gz $ cp -r Flask-0.6.1/flask ~/path/to/project/ (... repeat for other packages ...) There must be