i just discovered a cool firefox addon called yoono. It suggest others related site while you surfing the web. For example, you are visiting a site about money, yoono will then suggest other site which related to money or similiar to the site you're visiting. for more info and download go here:

https://addons.mozilla.org/en-US/firefox/addon/1833


p/s: don't ask me anything about it, i just download it and exploring .. :)