Presentation.io is a new service that is designed to help your audience follow along with your presentations. Presentation.io does this by allowing the members of your audience to see your slides on their laptops, iPads, and Android tablets and watch them change when you advance your slides. This ensures that everyone is on the same slide at the same time. Presentation.io includes a backchannel that allows your audience to comment on and ask questions about your slides.
To start using Presentation.io upload a PPT or PDF to your free Presentation.io account. Presentation.io then gives you a URL to distribute to your audience. When the members of your audience open that URL they will be able to see and follow along with your presentation. When you're done with your presentation just click "stop presenting" and the synchronization stops.
Presentation.io's free service allows you to share your presentations for 48 hours then you'll have to upload them again.
Applications for Education
Presentation.io could be a great little service for teachers to use in a 1:1 environment to make sure that their students are all following along with the presentation. You may also want to use the service to have your students share their presentations with you and their classmates when they're presenting to the class.