While holiday shopping I ran across this great little gadget for following the prices of items on Amazon. It is called The Tracktor.com and it allows you to set price alerts for any item on Amazon. This is great when you are not in a rush to get an item and are willing to wait until someone offers an item at a price you want to pay. Here is a screen shot for the Garmin 655t GPS Radio:
As you can see it shows you historical pricing and allows you set an alert for when they item you wish to buy reaches a certain price.
An even cooler thing about this site is that you can install an extension on your browser (Safari, Firefox, and Chrome supported) that will display the data you see on the left directly on your browser window while shopping at Amazon.com.
After you set up this service be sure to check your spam folder to make sure you are getting e-mails. Mine were delivered there for the first month.