I work with another developer and we have a project manager.
We talk to the PM once a week, or as and when required we can pop in. If we have a question we try to deal with it amongst ourselves, only taking it to the PM if we really need to.
Its structured quite flat and it works for us right now. The PM acts more of a filter than anything, as we have new systems we are working on and legacy systems to support, he decides where the time goes.
I do like to sit on my ass and read blogs / c9 etc...
Read "The Mythical Man Month" its a great read and really relevant to this. You'll enjoy it.