I found this craft in Country Living magazine a few years ago. It takes a lot of patience, but is definitely one of the neatest things I've ever made. The first photo is from the CL craft, the second is my version. :)
Find an old paperback book that you don't mind turning into a vase. Trace the shape you want your vase to be on the front cover and first few pages.
Begin cutting out the shape of the vase using an exacto knife or scissors. (I used scissors, and I have a feeling that a craft knife would work better.)
Continue cutting all the way through the pages of the book along the template, until you are done. This will take a while. Your book should now fan out in the shape of a vase.
Glue the front and back covers of the book together so that the vase will stand on it's base. You may have to glue a few of the first pages, or a page here and there to make sure the vase is uniform and well-balanced. Let dry, and you're done! It makes a nice vintage edition to your shelf or mantel.