If you working on some project or presentation and what to share the work with your fellow buddy that very second for some corrects or proofreading, then what you do?
Springnote is web 2.0 service which makes real-time collaboration on office documents and notes easy, here other users can comment, and add content as needed.
Springnote has all the features and capabilities of a word processor including all elements. You can add images, movies, audio, other presentation, and many other plugins. It also provides you with RSS to track changes in the documents and all activities made on it. But the main attraction of Springnote is its ability to allow real-time document sharing with other users you invite. Springnote also support publishing of the documents with 2GB of space, which I think is enough to host thousands of work documents.
Google Docs also sport a collaboration feature but I found the real-time on Springnote much more effective. Try it out and share if you have any more alternatives.