GNOME Dashboard "The Dashboard is a persistent rectangle of screen real estate on the right-hand-side of the user's screen. The goal of the dashboard is to display links to relevant objects as the user goes through his day-to-day activities." Screenshots here, and before graphing and after. The Dashboard developer blog is here.
Instrumenting Phone Manager for Dashboard "A recently implemented feature in Dashboard is cluepacket-rewriting. Cluepackets are the short XML messages applications send to Dashboard. Rewriting them enables backends to augment clues to help other backends. For instance, when an instant message comes in, the clue contains the remote user's nick and the content of the message. Your addressbook contains a mapping from an IM nick to an email address and home page URL. So, when the addressbook backend receives the clue, it augments it with the URL and email address. Other applications are then able to show more relevant information."