Congratulations to David Karger's Haystack team including Michael Bernstein and Max Van Kleek at MIT for the recent release of list.it. list.it is a simple light-weight tool for capturing 'information scraps'. It is a Firefox plug-in which provides a simple text box for entering short notes and sidebar to view, search, and organize the scraps. You can read the MIT press release.
The team also has a new paper on the system, Examining Personal Information Keeping in a Lightweight Note-Taking Tool, which was nominated for best technical paper at the upcoming CHI 2009 conference. You may also want to see the Haystack team's InfoScraps study that informed the system design.
If you are interested in design you should read the MIT UI Design Group blog, which includes posts from Michael and other contributors.