PriceSpy - PriceSpy helps you save money when shopping online.
Camelcamelcamel - Easily monitor Amazon product prices and get alerts when they drop.
Price Snoop - When viewing a product on Amazon, Price Snoop will show you just how much it costs on the other...
Penny Parrot - Get price drop alerts for products on Amazon as well as historical pricing to find the best deals.
Savelist - Found products you want but not ready to buy?
Fetchee - Fetchee is a free price tracking wish list app that works with all online stores worldwide.