I use my kindle all the time for this. I have a folder set up with folk music tunes I've downloaded, and one of the nicest features is the ability to go online (via the experimental web browser) and look up the lyrics to any song I'd like. I'm not sure that I'd be ready to use it as a music binder quite yet (size and setup might not be ideal for that), but it's great for folk music sessions. Fits in my purse too, which makes it a lot more convenient than lugging around my entire collection of music books.