Since upgrading OSX to version 10.7.3, when I attempt to run a Django \"syncdb\" command, I receive the following psycopg2 error from Postgresql 8.4.2:
psyco
This did the trick for me in the end...
Change the HOST value in the database dictionary in settings.py to this:
'HOST': '/tmp',
Source: http://jeffammons.net/2011/09/fixing-postgres-on-mac-10-7-tiger-for-django