Mac, Mindnode, freemind, NovaMind
Windows, X Mind, freemind
Only allows video between two parties, but is extremely smooth.
Web conferencing is used to conduct live meetings or presentations over the Internet. In a web conference, each participant sits at his or her own computer and is connected to other participants via the...
Offers more customization options than either pbwiki or wikispaces (without upgrading to the pay version).
Twitter for your org