MP3 audio city tours

Tourcaster.com offers 250 downloadable audio tours of more than 30 cities on six continents. They can be added to MP3 players, including iPods, or burned onto a CD. Most tours cost $5-$23 each, and each comes with a numbered map and detailed directions.

Example — the “Piazza del Popolo to Fontana di Trevi” tour of Rome takes 2½ hours, with an audio length of one hour nine minutes, and costs $19.90.

For many destinations in Europe, South America and Asia, the site offers 20- to 30-minute “audio guides” which are not tours and which cost $5-$10.