Larry has posted some photos of an under layout "crawler" that he's built. Kind of like the ones that mechanics use when working on cars, but it's a bit higher so he can easily reach the items he's working on. Due to the way the software works, the album shows as mine, since I created it, but the images, design and description are all by Larry.
http://www.modelrailroadforums.com/forum/index.php?media/albums/under-layout-comfort-crawler.3/
http://www.modelrailroadforums.com/forum/index.php?media/albums/under-layout-comfort-crawler.3/