Radioshift is the latest app from those audio obsessed fellows at Rogue Amoeba. Thanks the to included Radio Guide, which has over 50,000 internet streamed radio programs listed, this app allows you to find your favorite radio show and record it. The power of the app is that it doesn't just record the program once, but it will record every instance of the program. Your favorite radio show airs once a week? Set Radioshift to record the stream and forget it (until it starts to play on your iPod thanks to Radioshift's ability to add the shows to iTunes).
It is worth mentioning that Radioshift, out of the box, only records radio shows that offer up an internet stream. You can combine it with the radio SHARK to record Over the Air programs as well though.
Radioshift costs $32, and has a free trial available.