Sync.in is a web based word processor for people to collaborate in real-time.
When multiple people edit the same document simultaneously, any changes are instantly reflected on everyone's screen. The result is a new and productive way to collaborate with text documents, useful for meeting notes, brainstorming, project planning, training, and more.
Record screencasts for tutorials and share it via Twitter, etc. You can add voiceovers and limit the screen coverage (e.g. only inside your browser tab).