…unless you’re behind a school firewall.

[...] The first tool is called Think Free. I learned about it from Will. From what I can see, ThinkFree is pretty similar to Writely in terms of what it can do. Or rather, what you can do with it. I will have to investigate more to be sure. But at first glance I can say that it looks nicer than Writely. The second is called Writeboard. I learned about it from Blogging Pedagogy. Writeboard is different from Writely and ThinkFree in that you do not have a site that you can access where you find all your writing. Each document you create using Writeboard has its own url. Now, for occasional use, that would probably be fine. If you wanted to use it on a regular basis and involve a number of other people in the collaboration, it could get difficult to keep track of. Of course, these people have the perfect solution: another site they run called Backpack, which is free for limited use but can cost up to $5 a month for more extensive use. [...]

Talking about web goodness, have you tried pageflakes? Basically this is a portal framework which you fill with mini apps such as:
online storage at box.net or openomy, videos from youtube, writeboards, calendars, gmail, to dos, sticky notes, and a multitude of others. You can create multiple pages and set different sharing options for each page. The apps can be dragged around the page as needed. I’ve been playing around with pageflakes for a couple of days and it just keeps improving.

Looks like a pretty Netvibes…