A wiki is a kind of free-form website that is easy to edit. On a pbwiki, any visitor with the site's password can edit any page on the site. pbwikis can be made public to allow anyone to read a wiki, while still restricting editing to those who know the wiki's password. But pbwikis can be private, too.
Edits are done in plain text and don't require learning fancy or complex codes like HTML. Just start typing! It's also easy to create new pages and make links to pages you've already made.
Why might you want a pbwiki?
Sharing notes on Mayan culture for History class
Brainstorming the new product design for Tuesday's client presentation
Taking notes to figure out which digital camera to buy
Keeping track of the projects you're involved with and your TODO list It's profoundly simple to make a new wiki with pbwiki. It's totally free of charge and spam-free. With nothing to download, you'll be sharing information in a jiffy!
So go ahead and make a wiki! It's fun!