Product Observer is a browser addon for Firefox and Internet Explorer that can monitor the price of a chosen product on a shopping site and alert you when the price drops. This helps you save money as well as save yourself from having to keep track of the prices manually.
After installing Product Observer a blue button will appear on websites of supported shopping site and vendors. These are: Amazon, BestBuy.com, Borders.com, Overstock.com, Newegg.com, Argos.co.uk and Zappos.com.
Once you have decided on a product, click on this button to track the product you are currently looking at.
Next tell the Product Observer what you want to track price or user reviews. You can configure the browser plug-in to send you an alert when the price drops below a certain limit.
When prices drop or new user reviews appear, the icon of the Product Observer in the statusbar of your browser changes its color and the number of unread alerts is shown. Clicking on this icon offers a detailed summary of all products currently tracking, price change, number of reviews etc.