AAA Book Search Book search and price comparison at 44+ online bookstores. http://www.aaabooksearch.com/

AddAll Searches and compares prices among 41 on-line bookstores, including used and out of print titles. http://www.addall.com/

AllBookstores.com Search and compare prices at over 30 online bookstores by title, author, ISBN, or keyword. http://www.allbookstores.com/

Any Book For Less Compares prices at 22 online booksellers, including delivery to US, Canada and UK. http://www.anybook4less.com/

Best Book Deal Search and compare prices at 47 online bookstores. Calculates tax and shipping cost. http://www.bestbookdeal.com/

BookFinder.com Book shopping search engine, plus a meta search of 12 directories of used, rare, and out of print booksellers. http://www.bookfinder.com/

BookHQ Provides free listings, and searches new and used prices from ten bookstores. http://www.bookhq.com/

Compare Shop Books Gathers prices from about eight booksellers. http://www.compareshopbooks.com/

Fast Book Finder Searches by title, author, or isbn and compares prices among online booksellers. http://www.fastbookfinder.com/

ISBN.nu Compare prices at several online bookstores by ISBN, author, or keyword. http://www.isbn.nu/

Our Web Mall Compares prices of books at online stores. http://www.ourwebmall.com/

Price Owl Searches book stores and lists prices. http://www.priceowl.com/

Priceviewer.com Searches and compares prices among 47 book stores worldwide. http://www.priceviewer.com/

Search Biblio Online book search and comparison. http://www.searchbiblio.com/

TextbookLand.com Compares prices at fifteen online stores. http://www.textbookland.com/