Last Updated May 17, 2010 10:31 PM EDT
That's not a problem anymore, because we've got a PowerPoint add-in which lets you do exactly that, and for free, no less.
CircleDoc plugs into PowerPoint and lets you collaborate in real-time with other people on the same deck. The document owner can start a collaboration session, invite other people, and even chat, all within the PowerPoint interface.
One of the most interesting aspects of CircleDoc is the way it handles data synchronization -- it doesn't try to de-conflict conflicts, but instead just syncs all changes. That's fast and convenient, but somewhat dangerous, since competing changes can get lost in the process. The remedy? Make sure team members work only on complementary parts of a presentation, so no one steps on anyone else's work.
Another cool aspect of CircleDoc is that it lets you take a snapshot of the state of the document at any time, so it's easy to roll back to an older version or work on different iteration of the same presentation without explicitly saving different copies.
Wan to learn more? Check out this video for more details [via Lifehacker]: