I have yet to have the chance to participate in an Edchat discussion on Twitter, however I have spent some time looking over a few of the transcripts. I think this is a great tool/forum and look forward to participating in the near future. After looking over the transcript this evening, I decided to copy the text and create a Wordle (subtracting date, time, usernames, and other things like "RT", "@", and "#edchat")...it was easier than it might sound.
I thought it was neat to see the key topics discussed. I was also looking for a reason to play around with Wordle (a very cool tool!)
Here it is: