I am trying to set up a PostgreSQL database for my django project, which I believe I have done now thanks to the replies to my last question Problems setting up a postgreSQL
It seems that you need gcc-4.0, and it would be helpful to specify your OS type and version.
Maybe this question will help you a bit: Installing GCC to Mac OS X Leopard without installing Xcode
Update
I'm a Windows user, so I can't test your setup, but a quick google pointed to some more links: