The 75x20m banner ad for Apple's latest portable music gadget the iPod Nano completely covers the front of Glasgow's giant Debenhams department store on Argyle Street.

The poster site was unveiled by contractor Forrest Media, which was formed three years ago from the management buy-out of the ex-Score Outdoor division of media giant Clear Channel.

Apple is the first company to advertise on the site. Media buyer Posterscope bought the space for Apple and has also leased the site for the next 'in charge' period.