Online Tools for Educators -- and a Diigo demo

I was asked by a faculty member to create a list of online tools [view as list or slideshow] I use in the classroom. It was hard because I go back and forth with some tools, like mindmeister, that didn't make the list, versus mywebspiration, which did. Or for timelines, dipity versus timerime (not on the list).

Diigo can show your URL's as a  list :

or as a slideshow:

The show will rotate through each site (every 10 seconds), or you can click on the site you like.