NOTE: I would now recommend not to use Quicktime Broadcaster because of a nasty bug. For an alternative, see: /hugo/2005/04/advanced_podcas.html
It's burried in this page.
1. Make sure GUI Scripting is enabled.
2. Check 'Record to disk'. (Set the destination in the preferences.)
3. In the 'Video' tab: disable video.
4. In the 'Audio' tab: set the source to Soundflower.
5. In the 'Audio' tab: set the Compressor to Apple Lossless or your own preferred setting.
6. In the 'Network' tab: Set Transmission to 'Manual Unicast', Address to '127.0.0.1', Audio port '5432', Video port '5434'. (Optional: my buffer Delay is set to 8.)
7. Set the annotations! This ends up in the ID tags of the audio file. That is important.
For Podcasting, you will need to convert your file to MP3 afterwards. This can be done with iTunes.
The script that is given in the Apple page (above) does not work when you copy it. Do a search for 'check box' and replace with 'checkbox' first. (Or download the script here.) The script doesn't set everything as described above but it's a start and you can modify it for your own needs.