http://docs.google.com

See also www.zoho.com

Description:
Google Docs represents a new way of thinking about your files.  Instead of having a copy of your digital document on the hard drive of your computer and emailing it someone to share, you store the file on a Google server and edit it through a web page.  You can share out your document to others who can read it and even co-edit with you (in real time).  Make spreadsheets, documents for printing and even presentations.

Ideas for use:
Think of Word, Excel and Power Point in a web page.  Not only can you write your document and save it on the web so you can access it anywhere no matter what, but you can share the document and co-author with others.  Imagine your meeting agenda that everyone can directly edit… no more sending reminders and collecting agenda items.  Just share a Google Doc and presto: collaboration.

Considerations:
Don't keep private information in this kind of file as you don't really have total control over access; Google does.  This does require email accounts so be sure you have worked with parents if you want students to make use of this tool.