This is a superb site which allows you to make video of a drawing with audio. Combine this with a whiteboard and you can record a lesson quickly and easily and embed it on your site.
http://ictmagic.wikispaces.com/ICT+%26+Web+Tools
could be a simple way for students to create quickly create a mind map together. It could also be used by students to sketch diagrams and other drawings for use in slide presentations.