Data analysis is often an iterative and interactive process. However, when I present about this subject, I feel often limited by the presentation software I use. It doesn’t matter if I use LaTeX/PDF, PowerPoint or Keynote. In all cases it is either very difficult or impossible to include interactive charts, such as Flash or SVG charts. As a result I have to switch between various applications during the talk. This can be fun, but quite often it is not.
Now imagine a presentation hosted on a server with R installed! You could combine your slides with R using one of the following packages R.rsp, brew, Rook, etc and run live demos, without opening a console.