How do I develop against OAuth locally?
You could create 2 applications? 1 for deployment and the other for testing. 
Alternatively, you can also include an oauth_callback parameter when you requesting for a request token. Some providers will redirect to the url specified by oauth_callback (eg. Twitter, Google) but some will ignore this callback url and redirect to the one specified during configuration (eg. Yahoo)
I'm building a Python application that needs to communicate with an OAuth service provider.  The SP requires me to specify a callback URL.  Specifying localhost obviously  won't work.  I'm unable to set up a public facing server.  Any ideas besides paying for server/hosting?  Is this even possible?