The vast majority of e-book sales at the moment are being rung up in the US, and most of these are being read on portable devices specifically designed for the task.

These include the SoftBook and the Rocket eBook, which retail for a few hundred dollars. They are reasonably slimline devices that basically duplicate the traditional book format. You download your titles from any one of hundreds of sources on the Internet, and you pay around the same as the bookstore price.

Analysts seem convinced, though, that most future e-books will use technology such as the Microsoft Reader programme, which presents a facsimile of the book-reading experience on your laptop or palm pilot or on your PC. It comes complete with various extras, such as a built-in dictionary.