SlightSync is a pet project of mine and should allow you to watch a presentation or some photos together with other people in a synchronized way. It's still in development, but I'm definitely interested in some beta-testers.
If you want to give this web application a try, you can access the main site here, or just click the image above. If you don't have the time to create your own slides, you can just try out the demo presentation.
Your feedback is always welcome at
jori.liesenborgs at gmail.com