http://del.icio.us Del icio us.  Del.icio.us is a social bookmarking website -- the primary use of del.icio.us is to store your bookmarks online, which allows you to access the same bookmarks from any computer and add bookmarks from anywhere, too. On del.icio.us, you can use tags to organize and remember your bookmarks, which is a much more flexible system than folders.

www.diigo.com Diigo Diigo provides a browser add-on that can really improve your research productivity. As you read on the web, instead of just bookmarking, you canhighlight portions of web pages that are of particular interest to you. You can also attach sticky notes to specific parts of web pages. Unlike most other web "highlighters" that merely clip, Diigo highlights and sticky notes are persistent in the sense that whenever you return to the original web page, you will see your highlights and sticky notes superimposed on the original page, just what you would expect if you highlighted or wrote on a book!  Moreover, all the information -- highlighted paragraphs, sticky notes, and the original url -- are saved on Diigo servers, creating your personal digest of the web, your own collection of highlights from the web - ones that are meaningful to you! 

http://www.portaportal.com PortaPortal  Portaportal is a web based bookmarking utility that lets you store links to your favorite websites online. Now your bookmarks are no longer limited to any one machine. Then, the next time you come across a website that you like, simply copy the URL, come here and add it to your portal. This way no matter where you are when you surf the web, the bookmark will be waiting for you