Bookcost does not state who or how many sites it searches, but appears to hit most of the majors and several others, perhaps more tilted toward new books. Single field search. Displays shipping costs. Not good for rare books. Link: www.bookcost.com

FindBookPrices is relatively new. Does not list where it searches. Appears tilted toward new books, but does search Alibris and Abe. Single field search. Displays shipping cost. Did not find very much. Link: findbookprices.com

BestBookBuys (BestWebBuys) searches 25 sites, including Abe, Alibris and other majors with a tilt toward newer books. Searches just one field at a time. Displays shipping cost and time, and unusually, for which states each site collects sales tax. Another one that misses the older books. Link: www.bestwebbuys.com

Any Book International searches 10 sites, with just three listed for old books – Alibris, ElephantBooks, and Half. However, they seem to show only dedicated search boxes for Alibris and Amazon. Not sure what is going on here. Link: www.anybook.com

AnyBook4Less searches 25 sites, including Amazon, Abe, B&N, Half, Wal Mart, Overstock and Chapters. One field search. A search first takes you to a page with details about the edition and customer reviews. A second click brings you to copies offered, including shipping costs and timing. Seems to find mostly new books. Missed a lot. Link: www.anybok4less.com

AKA Book is a relatively recent site searching 42 listings sites, including Abe, Alibris, Choose, B&N, Amazon, Half, eBay and lots of new and textbook sites. Can search either by keywords or author and title. Includes shipping costs. Separates new books from used. Did not find anything old. Link: www.akabook.com

All Discount Books claims 110 sites, but does not specify them. Appears to hit most major sites. One field at a time search. Shows shipping costs and times. Another one not targeted to the antiquarian. Was painfully slow at the time we tried it. Link: www.alldiscountbooks.net

The Cheapest Book claims 40 unstated stores. Amazon, Alibris, Overstock, Powell's and Blackwells are among them. Two search fields. Search first goes to a descriptive page, second click to see matches. Shows shipping. Finds mostly new books. Fast, but said some books were "only available at Amazon" that we knew were available elsewhere. Link: thecheapestbook.com

Get Cheap Books does not say how many sites, but reaches the usual subjects. One search field. First goes to page of data and Amazon reviews, second click to listings. Shows shipping. Not much old material. Link: www.getcheapbooks.com