As some of you may know, I have spent the better part of "adulthood" in higher education. As a result, I've acquired enough textbooks and case books to give any sane human a stomach ache. While I've held on to many of them for reference, they are certainly an eyesore.
I have a simple solution. All you need is paint, doilies, and some Mod Podge.
After painting the spines, I simply applied a bit of Mod Podge to the back of the doilies (also painted) and pressed them firmly onto the books until [relatively] dry.
(If you're apprehensive about painting the books themselves, you can easily make book covers for them and simply paint those.)
This is a great project to do with all the left over paint you have, as it ties in all the colors you've used on other items throughout your home.