We've all been there, wandering the isles at the local book store, row after row of computer-related titles stretching before you. You're looking for something to further your knowledge, give you the opportunity to overcome that challenge at work, or maybe even just learn more about a cool new feature of PHP. But, is it worth it?

Do you think it's worth spending your hard-earned cash to get a book that's possibly already out of date, or will very quickly be? Is the internet becoming "the place" to go for all things PHP-related? More and more, PHP books are being replaced by online documentation (of which the PHP manual is the best), but, starting out in the world of PHP can be daunting. A few books can help, but after they guide you into the right mode of thinking, are they worth anything anymore?

What do you all think? Are your PHP books just collecting dust on the shelf, or are they your constant companion in your programming experience?