BBC Backstage ran a Widget competition in October 2006 and, hey, something wot I wrote won!
The BBC Radio Live'n'byNet widget 'tunes' into all of the BBC's Live radio streams as provided by the experimental BBC programmes API, essentially BBC Radio 1 thru 7 + the world service and asian. It provides channel listings and setting of 'alarms' on programmes. It relies on the Zeepe web application/widget framework and is free to use.