There are some web streaming-only audio shows I occasionally listen in on, and I wanted to record some of them. (Three points if you can guess which archived show pushed me over on this.) The old Wiretap program hasn't been updated in a while, but there're two newer – and less expensive – games in town: Audio Hijack and Piezo from Rogue Amoeba software. Piezo is dirt-simple to use and costs only $15, and it puts out OK-quality mp3 recordings of whatever you happen to be streaming. Up the scale, Hijack is merely very easy to use and can put out higher quality audio files in different formats. It runs about $30.
You can download and do a free ten minute trial from the above links. After ten minutes they still work, but there's some noise inserted and you pretty much will want to either buy or stop using. Ten minutes though is plenty of time to see if it'll work on your machine, has the features you want, try a few options, make a few test recordings, and to see if the cheaper Piezo is good enough for your needs. After trying both I went with Hijack, wasn't that much more money for a lot more flexibility.
Nice stuff, recommended.