Just how useful is a small LCD screen attached to a laptop? While at first many were skeptical, it seems the idea of a sideshow LCD screen, whether detachable or built in to a laptop, is beginning to take off. Particularly with the support that Vista brings, more hardware is turning up with the devices. Some of them are built into the exterior cover of a laptop, some are built into the relatively unused surface areas near a laptop's touchpad. Going beyond just displays, some companies are looking to make them quite robust:

Some inventive engineers have taken Preface technology to another level by taking an MSI Mega Player 529 media player and integrating into a notebook as a SideShow device. The 1GB Mega Player 529 is originally spec'd to playback MP3 and WMA audio files as well as MJPEG files via its 2.5" display. As a SideShow device, the Mega Player 529 is able to take on some more important roles like viewing email and PowerPoint presentations.
Where exactly is the practical use for this? Aside from being able to demo a product easier on the shelf, there are many areas in which a feature like this could be attractive. Customization comes to mind, or implementing some of the “quicker” functions of a PDA into a more robust laptop without worrying so much about the inferior battery life. Interestingly enough, adding one of these panels to new laptops is quoted at a mere $40. Even if you don't see an immediate use for it, for $40 I'd be willing to try.