Photo credit: Mipan

1. Trillian Astra: Multi-protocol instant messenger allows you to connect to multiple IM services either with client and web-based version
2. Collanos Workplace: Free P2P software allows you to form teams and collaborate on shared projects with other people
3. 21Classes: Website enables teachers to set up a classroom blog and to manage students' blogs
4. Writewith: Collaborative writing tool allows you to edit documents with other people

1. Trillian Astra
   
   
   
   Trillian Astra is a multi-protocol instant messenger that can connect to multiple IM services, such as AIM, ICQ, Windows Live Messenger, Yahoo! Messenger, IRC, Skype and Google Talk networks. Plus, if you're not at home or haven't installed the client on your machine, you are able to communicate with other people anywhere your are with the web-based version of Trillian Astra, available on your personal home page. Beta
   
   http://www.trillianastra.com/





2. Collanos Workplace
   
   Collanos Workplace is a peer-to-peer team collaboration suite. It allows internet users to form teams and collaborate together on a shared projects. Available for Mac, Windows, and Linux PCs it enables users to invite colleagues, friends, or partners to a team workspace where members can immediately share and organize their files, notes and links, lead discussions, and assign tasks. Free
   http://www.collanos.com/m1/en/index





3. 21Classes
   
   21Classes is a website that allows teachers to set up a classroom blog and to administer students' blogs. Every class will have its Class-homepage where students can register and login into their own pages, find new blog entries, news and assignments from their teacher, and upload images and videos. 21Classes is 100% web-based and free to use
   http://www.21classes.com/





4. Writewith
   
   Writewith is a collaborative writing tool for editing documents together. You can upload a document to the site (.doc, .txt, .rtf, Open Office) and invite other people to see, edit and chat in real-time. If they don't have an account, they can edit the document by email without their needing to create an account. a message board, and task assignments.
   http://writewith.com/