Something new, introduced by BY two days ago... interesting... it's called voicethread (http://voicethread.com/#home).
First impression: It produces a multimedia presentation that allows once to add commentary - in the form of voice, text or even 'freehand' sketching - be it by the author or the viewer.
Hm... would say, it's slideshow that comes alive?!
Saw one interesting production by a 10-year old boy on his trip to Washington DC this March.
This gives me some ideas for this web application to be used:
1. Language - get pupils narrate an experience/story? (eg. http://voicethread.com/share/87609/)
2. Get pupils to describe a process - this could be science? maths?
3. Fieldtrip - as shown in the example
4. Combining the above, it could be interdisciplinary, too...