Take a tour of New York with a star as your guide
Picture the scene: you are standing at the intersection of Church Street and Fulton Street in Lower Manhattan, with the World Trade Centre site to the right. To the left is the churchyard of St Paul's Chapel. You could tour New York City on your own, but wouldn't it be great to have a local guide?
What about actress Sigourney Weaver, with her honey-husky intonation? For the cost of a book of subway tickets Weaver can now be hired to whisper snippets of Manhattan fact and lore into your ear as you walk around historic New York City.
She will tell you, for example, of Alexander Hamilton, the architect of American capitalism, and his ignominious death by dual, or of the architectural challenges of restoring the New York skyline after the September 11, 2001 terrorist attacks.
Weaver is one among the many New York notables who have been picked by Talking Street (talkingstreet.com) to share their neighbourhoods with tourists, via travel podcasts that look set to change the way we see the world.
Other celebrities include actor Ben Stiller, who has given voice to his Lower East Side.
Podcasts are ideally suited for spoken-word travel guides to be listened to at the destination. While podcasts could never be as comprehensive as a guidebook, they are easy to use with an MP3 player and are often free.
And unlike difficult-to-fold maps, a pair of white earphones do not say 'tourist'. Travellers can wander the streets and when in need of some local knowledge, they can scroll to the relevant podcast.
The main players in the podcast travel guide market are the large brands, such as Rough Guides (which offers walking tours of Glasgow's music scene, literary London, Paris, Prague, New York and California at roughguide.com/podcasts) and Lonely Planet, with its series of interviews with travellers from the Yucatan to St Petersburg (lonelyplanet.com/podcasts).
There is also a host of newcomers, including Travelstreet.com, Soundwalk.com and Soundsforsights.com. Soundwalk charges an average of US$12 and has cornered the market for New York City with quirky, off-the-beaten-track tours such as Bronx graffiti and a Williamsburg Hasidic Walk. It also covers France and India.
Sounds For Sights charges US$4.99 and offers sound tours of New York's financial district, Boston and Washington.
Across the pond, local councils have got in on the act too. Dublin's iWalks are available through the local tourist office at www.visitdublin.com. A short podcast for Edinburgh is available at www.visitscotland.com/sitewide/edinburghpodcast. And at www.handheldtours.net you can download Dickens and Shakespeare tours of London.
Charging for podcasts is arbitrary, even in the corporate world. Virgin Atlantic (virginatlantic.loudish.com) offers free destination guides for seven destinations - including Cape Town, Cuba, Dubai, and Johannesburg - and plans to expand to 26 destinations soon.
The Guardian Online (travel.guardian.co.uk/audio/soundsofthecity/) is also offering free titles, among them Athens, Marseilles, Valencia and Nice, with content compiled by Guardian writers.
The next step could be travel podcasts combined with GPS technology, using mobile phones to alert tourists when they pass a 'tagged' point of interest. The first such system recently premiered to high acclaim in Venice (www.planetaudioguide.com).
There is little doubt podcasting is still in its embryonic stages, but the technology has huge potential and 'sound seeing' holds promise of being much more than just the latest travel trend.
The humble guidebook may well have met its match.