Video web site Videojug details how to install "invisible" bookshelves that make your books appear to be floating on nothing. The tutorial requires one large book you're willing to sacrifice, an L-bracket, and a few other common supplies. We've covered the invisible bookshelf once before, but the video provides a much more detailed account of the process (despite the unnaturally loud narration). Like the original, it's just as good and a lot cheaper than the commercial version. Looking for other inventive ways to sacrifice books? Try the iPod carrier or secret hollow book.