How do I run a headless testnet on OS X? I'm trying to develop some applications and need bitcoind, but can't seem to find a recent version. Posts seem to indicate that it's incorporated into Bitcoin-Qt, but I don't want to run a GUI just for headless RPC calls.

So how do I set up a testnet on OS X?

How to setup testnet-in-a-box on Mac OSX? seems like it would work, except I don't have the bitcoind command for whatever reason.
Ready to use distribution of bitcoind for Mac OS X doesn't exist, so you would have to build it from source code, here is the instructions for that: What are the steps in building bitcoind on Mac OS X 10.6?