Contexted is a free note-taking tool that converts your notes into a Mind-Map.
UberNote offers many ways to save your research notes: via a toolbar that you add to your browser, email, instant messenger, mobile device or even on their own website.
Transno is an interesting mind mapping tool because it will create mind maps based on your written outlines. Take a look at this video www.freetech4teachers.com
Marqueed is a service that allows users to create and discuss collections of images and PDFs. Using Marqueed you can highlight and draw on images as well as PDFs. You can share MarQueed files or keep your files private. Likewise you can create private and public collections of files.
Notalon: for the Cornell, dual-entry note-taking
Webklipper: Take notes on any page
iLeonardo: Combines social networking with research
YoLink: Find materials and export into Google Docs: For writing papers