Although I'd much rather read a book in front of me, I recently subscribed to Oreilly's Safari Book service.
http://safari.oreilly.com/
You can check out 10 books at a time for $14.99/mo . It's not just Oreilly books too.
You can search through the current book you're reading, all the books on your book shelf, or even all the books in the safari collection. It also gives you the option to search just code fragments.
Just thought I'd pass the word along.