A few software are now allowing this type of interactive collaboration, called multiple mice or single-screen groupware. Wunderworks offers a free download of their software that lets you connect 3 mice, and each will have a different color. It can be used with any software, so I have tested it with a mapping software, and asked 3 students to move objects at the same time. Technically it works very fine, I think the challenge is in the task!!
Microsoft offers the Mouse Mischief, to be used with Powerpoint for educative purposes. It’s free and easy to install. It seems that the target are joung children since the mouse icons are represented by animals. I’m looking forward to test it in class.