I'm in between projects at work, so I have a little time to kill. I've been doing a quick scan of all my stared RSS articles on Google reader (which is a great RSS app by the way) and I came across this list of useful applications for learning (both freeware and payware).
Out of this list, I found the following apps notable.
http://www.ustream.tv/ - a free web streaming service
http://www.teachertube.com/ - a site that host youtube type videos for learning.
http://www.mindmeister.com/ - a collaborate mind mapping site
classtools.net - a Flash game creator site for educational purposes