Open Source Campfire plugin for iChat
g-off.github.comDoesn't appear to be a binary available, only the source. I tried running it from Xcode, but looks like I'm missing some dependencies. I could track them down probably, but will probably just pass on it for now as it looks pretty beta.
There's an installer in the text of the page at http://g-off.github.com/Campfire/
No tracking down of dependencies necessary, they are all submodules. You just need to git submodule init, git submodule update.