TitanPad is a free tool that allows you to quickly create an online place to collaboratively create documents with one or more partners. You do not need to register in order to use the service. You can chat in real-time while creating a document. Every person contributing to the documents you build is assigned a highlight color so that you can easily track who wrote what in the document. In the video embedded below I provide a demonstration of how to use TitanPad.

Applications for Education
Google Documents is great for collaborative writing, but not everyone has Google Documents. Google Documents also requires sign-in in order to track changes. When you want to quickly collaboratively create a set of notes, TitanPad is a good option to pursue. I first saw it used during a BarCamp (the partial inspiration and predecessor to EdCamp) meeting in which presentation attendees used it to take notes.