Free iPad app: http://itunes.apple.com/us/app/gather-education-classroom/id525319815?mt=8&uo=4&at=10l6SU
Website: http://gathereducation.com/
Free Mac program: http://www.google.com/tools/dlpage/res/talkvideo/hangouts/
Free Windows program: http://www.google.com/tools/dlpage/res/talkvideo/hangouts/
Website: http://www.google.com/tools/dlpage/res/talkvideo/hangouts/
Google Chrome app: https://chrome.google.com/webstore/detail/google%2B-hangouts/kbpgddbgniojgndnhlkjbkpknjhppkbk
Paid iPad app: http://itunes.apple.com/us/app/popplet/id374151636?mt=8&uo=4&at=10l6SU
Paid iPhone app: http://itunes.apple.com/us/app/popplet/id374151636?mt=8&uo=4&at=10l6SU
Website: http://popplet.com/
Website: http://www.titanpad.com
Website: http://www.globalschoolnet.org/
Paid iPad app: http://itunes.apple.com/us/app/collaborize-classroom-pro/id512701825?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/collaborize-classroom/id497540468?mt=8&uo=4&at=10l6SU
Website: http://www.collaborizeclassroom.com/
Website: http://todaysmeet.com/
Website: https://www.google.com/apps/edu/