Sliderocket is something I've heard about but never used until today. It is a standalone site but also is a web app in the Google Chrome OS Store, so I started trying it out.

Sliderocket is a free online presentation software (similar to an online version of PowerPoint or Google Docs) that has some really great features. You can create a new presentation or even upload an existing PowerPoint presentation to the site. You can easily add photos from your library or from the internet with Flickr as a choice. Videos are simply installed and embedded. Slide transitions are supported along with allowing viewers to comment on each slide. You can embed Twitter feeds as well as a variety of other features.

Sliderocket has a very good demo/tutorial that walks you through the steps of using it. There is also a good help section and plenty of people using it that post information online.

I found it easy to use and very powerful and will be using the Chrome OS webapp version quite a bit now.

It's very useful for education. Students can interact and collaborate on presentations. Teachers could post presentations and have students comment on the slides. The presentations are also more interactive and have some cool features that PowerPoint doesn't have.

You can even integrate SlideRocket into your Google Apps account.

There is a free version with some limitations and a fee-based version with more features.