A.nnotate.com lets you easily give, collect, and store detailed notes on documents and Web pages. A.nnotate is an online Web service for sharing notes on documents and web pages using a Web browser. No software or plugins need to be installed - it works within the Web browser and currently supports Firefox, Internet Explorer 7, IE6, and Safari. Supported document formats include: PDF, Microsoft Word, Microsoft PowerPoint, Microsoft Excel, Rich Text Format, OpenOffice documents and spreadsheets, and HTML Web pages.
Firefox, Internet Explorer 6 or 7, Safari