Preso.tv is a neat service for sharing slideshow presentations. Through Preso.tv you can broadcast your slides to the laptops and iPads of everyone in the room with you. To broadcast your slides you must first upload them to Preso.tv. After uploading your slides Preso.tv will provide you with a link to share with your audience. When people use your Preso.tv link they will be able to follow your slides on their laptops or iPads. An alternative way for people to join your slideshow is to visit Preso.tv and allow Preso.tv to access their location after which they will see your slides. (Note, that feature only works when you're audience is in close proximity to you).
Applications for Education
Using Preso.tv could be a good way to keep your students on the same slide that you're projecting. Likewise, Preso.tv provides a good way for students to share with classmates. A chat feature is built into Preso.tv. Students could use the chat feature to ask clarifying questions about each slide that they see.