simplegeo’s python-oauth2. The Python OAuth library scene is frighteningly complicated at the moment. This seems to be the most actively maintained, and the readme includes working example code for talking to the Twitter API (including integration with Django auth).

django-piston. Promising looking Django mini-framework for creating RESTful APIs, from the bitbucket team. Ticks all of Jacob’s boxes, even including built-in pluggable authentication support with HTTP Basic, Digest and OAuth out of the box.