/ Gloobus-Preview is an extension for the Gnome Desktop Environment designed to enable a full screen preview of any kind of file. It's based on Apple's "Quicklook".
/ CoverGloobus allows you to see at a glance your currently playing song, with album artwork and ratings.
/ The Coverflow mode lets you browse thought your files visually, by flipping around the icons of your folders and documents. Each file is displayed as a large preview of its first page, so you can actually see the contents of a document before opening it.