Authorstream is a clever application that you can use to publish and share your Powerpoint presentations on the net. Whether you are a teacher, student or businessperson wanting to share presentations with your colleagues or just wanting to share photos and greetings with friends and family, Authorstream offers this service free of charge.

All you need to do is register, import your contacts list and start uploading presentations. The site allows you to make them public or private, and even converts them into an iPod and YouTube friendly version.

Once the upload is processed, you’ll get a direct URL and even the coding to embed it and create a thumbnail, if you want to post the presentation to your own website or blog.