Another nice feature of these sites is that they provide a number of ways in which you can share presentations with others. One way is to embed the presentation into a blog or web page. These embedded presentations can then be viewed on that site, shareed with others, or even taken and re-embedded on your own site or as a Facebook post. For example, here is an embedded presentation that I sent to my family yesterday that given some context to the earthquake in Haiti (just use the controls below the image to go forward or backward in the presentation:
Haiti Earthquake 12 January 2010
View more presentations from kevinrchapman.
I hope you take some time to explore these sites for content that may help your students and you. Feel free to reply to this post with some favorites.
Tim