On a PC, capturing streamed audio is relatively easy, but on a Mac it is another matter. Things reached boiling point this morning when I badly wanted to listen to a programme about the number of UK politicians being paid for from the public purse, but helping my wife with her final day of preparation before the dreaded GMAT exam was more urgent. I just couldn't get my MacBook to record the audio stream and had to give up and get back to the high-priority task.
However, to complicate the picture further, Ambrosia no longer supports WireTap Pro, though it did release a last final version for OS 10.5. I managed to track down this official URL and downloaded a trial copy from here. But with the same insistence of their lady announcer, Ambrosia make it pretty clear that they would much rather you bought WireTap Studio. When you install WireTap Pro you get a message and link that says there is a new version - but there isn't. The link takes you to ... WireTap Studio. I think this kind of message is misleading, especially if you have bought the registered version (for $19).
I prefer the new interface of Studio to Pro, and it also offers the chance to organise your library of recordings. The trial version of Studio lasts for 30 days, but appears to be a full working version. I like the fact that you can select two inputs at once, though I am not sure you can change the volume of either. A really nice feature of both WireTap Pro and Studio is that you can set the software to record in advance and for a definite time, which could be extremely useful if you have to go out hours in advance of a much desired programme and don't want to record everything before that (which I suppose in the worst case could cause your computer to crash). You will still have to leave your computer on and streaming - I have not seen a sleep state that automatically wakes itself up at a certain time and fires up requisite programs and streams. Maybe it's out there - do let me know, if it is.