MindMeister for Mind Mapping (Webbing)

From the MindMeister website:
"MindMeister supports all the standard features of a classic mind mapping tool - only online, and with as many simultaneous users as you like!"

Invite users to collaborate on a map or just view it. Publish it to the web for all to see if you like. You can even

Some shortcuts I found - enter/return and tab are the keys you will use most. Enter/return cements your text. Press enter again and you get a new bubble at the same level. Press tab and you get a bubble attached to your current bubble. Drag the bubbles around to rearrange, though it is quite picky about where you drop things. If it's not doing you want it to, try dropping the bubble on top of the one you want to attach to.

http://www.mindmeister.com/