There's also another program for obtaining streamed MP3 called "Aquisition". Search http://www.versiontracker.com/macosx/ to see if it's there. If not, I can email it to you. I have both Aquisition and RadioFree, though I've never used them. My 56K connection is too slow to capture anything worth saving.
Better grab while you can, after October, most MP3 radio stations will disappear due to licensing restrictions (0.14 cents per stream). The stations simply cannot afford to pay the RIAA that kind of money.