I've been finding out some more about the Long Pen, the bizarre but fascinating gadget we first mentioned in our Ticket Alert on the Book Festival's programme launch.  Using this remarkable gizmo, two authors - Canada's Alice Munro and Pulitzer Prize-winning Norman Mailer - will "sign" books in Edinburgh from the comfort of their homes on the far side of the Atlantic, with the aid of a video link and a remote-controlled pen.

You can sneak a peek at the LongPen in action in these videos on the manufactuer's website.  The extraordinary thing to my mind isn't the technology - I made something a bit like that out of Meccano, when I was ten - but the commercial logic the videos reveal.  They make no secret of the fact the invention is designed to help authors sell more of their books to more of the world... without the crushing inconvenience of having to leave their homes.

The customers seem satsfied enough, having enjoyed a good chunk of video-enabled face-to-face time with the author, and the environmental argument is particularly hard to fault.  But aren't we losing something here?  Isn't the pleasure of owning a signed book the knowledge that you are turning the very pages the author turned - touching the very cover they touched?  Will it really feel the same when it's a facsimile signature, reproduced, however faithfully and individually, by a machine?