This is not exactly a deal that you can go and buy, but definitely something every HUKD user should know about (and I'm sure most of you do, but for those who don't)...
Its basically a site that tracks the price history of all products on Amazon (and a few other sites too). If you are about to buy something, its always worth checking here to see if the price has ever been cheaper. Since Amazons pricing model means that prices can fluctuate many times a day, you often find that if you wait a bit, you can get it much cheaper. To make all that even easier, you can set up price watch alerts that will email you when the price falls to a value you want.
Read more about it here, its definitely worth the hassle of getting it set up and setting up some alerts...http://uk.camelcamelcamel.com/features
Chrome and Firefox both have plugins that can be used to make tracking a product much quicker as you can simply click on the button from the Amazon product page...http://camelcamelcamel.com/camelizer