Voicethread is a free website which describes itself as "A tool for having conversations around media".

To find out more about Voicethread view this: http://voicethread.com/#home

See also the pdf: Classroom Guide to Voicethread

An easy to read pdf version of the guide in book form

Examples of Voicethread use http://eastnet.wikispaces.com/Voicethreads and see this Haiku example or this example based on the on the book When Donkeys Fly. You should also see my Voicethread blogpost.

There is an educators' version of Voicethread which provides a more secure environment and unlimited voicethreads but is expensive. There is also an ipad app available that gives you 5 free voicethreads - can delete old ones to add new ones.

Another example - this one by Kindergarten students talking about trout hatchlings.