Dave, a new Slow Travel member, has prepared 3 walking tour itineraries of Rome in both Streaming Video and MP3 formats. I've looked at the videos and this evening I've downloaded the MP3 files onto an iPod. The tours look great - one starts a the Colosseum, one at Piazza del Poppolo and one at the Spanish Steps. I'm sure we'll try to follow them when we're in Rome - another great Slow Travel find.
Here's a link to the files.