Want to buy a blu-ray movie, but not interested in paying full price? Search on CamelCamelCamel for what you want then subscribe to the associated “3rd party used price” RSS feed (look for the RSS icon: 
). You’ll get an RSS update each time the price changes.
WHAT IF you could subscribe to your favorite websites and automatically be sent any new articles they post instead of checking back a couple times a day or week to see if there is anything new? Wouldn’t that be great? The future is now! Head over to Google Reader, sign up for an account, then click the ‘add subscription’ button. Type in the URL of the website you want to subscribe to and if it supports subscriptions (aka RSS) you’ll be reading their articles in seconds. Try it on all sorts of sites: works with this blog, newspapers, interesting discussions in forums, and plenty of other webpages.