Dude, why are all those Princess passengers wearing iPods?

Guide-led walking tours are a great way to get to know a city, particularly in Europe where many urban centres are compact and pedestrian friendly. But they can be a drag if you get stuck with a big group. And they don't offer a lot of flexibility. Where the group goes, you go.

Enter Princess Cruises, which is launching do-it-yourself iPod walking tours this summer in more than a dozen European ports.

For £15, passengers will get a detailed map showing the best route between top attractions and an iPod to use for the day loaded with recorded tour information about each site listed on the map. Then they can set off at their own pace.