I pretty much started hyperventilating when I saw this video for Twiddla, as the video states a "meeting playground".
If it's also free (for educators and students) - I may need to get a paper bag so I can breathe. Check out the link below. Presenter embeds a slide-share presentation and a backchat - which he shows how to simply code for... OMG - Way too cool!!
It's a platform for multiple tools which can be seen all at once!
The basic service is free for everyone. But for more "deluxe" services there is a cost $14/month min... But if you are a teacher sign up and email them your school address and you get a free account!! For more info. go to Twiddla and checkout the "Features" page - Scroll to the the bottom, and read the "For Teachers" section.
COOL X 1000 000!!