Collaboration tools
Google Apps
Web & App
http://www.google.com/educators/tools.html
Voice Thread
Web & App
http://voicethread.com/
Delicious
Web & App
http://delicious.com/
Diigo
Web & App
http://www.diigo.com/
Etherpad
Web
http://etherpad.com
Linoit
Stickies students and teachers can use to post ideas and communicate on the web.
Web & App
http://www.linoit.com
Web & App
http://www.twitter.com
Voki
Web
http://www.voki.com
Screencasting
Produce your own tutorials by recording every move made on your computer screen
Web
http://www.screencast-o-matic.com/