Attention.XML is an open standard, built on open source (see XOXOSampleCode) that helps you keep track of what you've read, what you're spending time on, and what you should be paying attention to.
Greasemonkey is a Firefox extension which lets you to add bits of DHTML ("user scripts") to any web page to change its behavior. In much the same way that user CSS lets you take control of a web page's style, user scripts let you easily control any aspect of a web page's design or interaction.
