Just been researching some online tools, and found these links useful:

http://www.c4lpt.co.uk/recommended/ (list of education related tools)

http://www.slideshare.net

http://photopeach.com/

http://www.flypaper.com

http://prezi.com/

http://www.slide.com/

http://www.jingproject.com/ – a simple screen capture and sharing system

Camtasia – screen capture and editing software

ispring pro – PPT to flash converter

http://animoto.com – online video creator (from photos)