Here is a
GIANT list of OS X audio applications. They range from stand alone audio routers to complex editing programs, from freeware to pay ware.
If you don't want to read the list provided above, then here are some options.
Wiretap is a routing and recording program similar to
Audio Hijack. You can rip and record from streams, DVDs, speakers, jacks, and the microphone. Both are good programs, and the limited version of WireTap is free. They are combined audio routing and recording programs. I use WireTap, it's less expensive, and just as good (if less featured than AudioHijack).
iNet Stream is not a recorder for your Mic or Line-in, or USB or Firewire sound card, but it will record streams very well! It can strip off the coding so that it is iTunes compatible, that is it can take song and station data so when you import it it is read for iTunes with out you typing anything. When you give a station a name, you can set its Genera and other iTunes tags. It is worth the 15 bucks, but off course this is only used to run quality control on your own streaming audio. Just drag the iTunes stream to its window, fill in some text, and your there. If you have access to a good digital line, you can even record multiple high-bit-rate streams with out any glitches. I recommend only recording one stream at a time, and generally don't listen to it in real time, incase there is some network lag. I love this program! It doesn’t record system noises, which AudioHijack and WireTap do (depending on settings). Try the free trial, the ability to "save" streams as seperate files with all of the artist/name/etc data is pretty cool.
If you have specific questions about any of the Mac audio apps, post them, and I am sure you will find at least one user who can comment on them.
I work as an audio-monkey(engineer), using mostly PC and software. I will say that Pro-tools is not for everyone.
There are other ways to extract out audio from a stream, but these are simple, single applications that can do it.
