Okay, it's time for a nerd moment, but I'm pretty excited about this. Of course everybody knows they can get lots of information on a book from Amazon, and little features that let you view the covers and table of contents are the next best thing to browsing in a shop and the "Search this Book" feature is great for those of us who just want to find obscure references in a volume without finding the actual book first. (Of course, you know that if you order from Bean Books, you get comparable prices and get to deal with a real person, right? Bill is my book source...).
However, if you're on a tighter budget and need to track down particular books in a library, WorldCat will help you out. Check out worldcat.org. Type in a title or author, and select the book you're looking for. Enter your zip code, and then you'll be offered a list of nearby libraries that carry the selection. Isn't that amazing?
Hooray for librarians!