The first tool I am going to share is called Cacoo
Cacoo is an online drawing tool that makes Real-Time Collaboration a reality!
Cacoo enables Real-Time Collaboration. A diagram created with Cacoo can be edited by multiple people at the same time. Changes by users are reflected in real-time. Working with Cacoo makes it seem like everyone is working together in the same room and brings new meaning to the word Collaboration. (www.cacoo.com)
I have had a little play with this and thought you might like to see an example of it. I am thinking about the possibly of using this tool in my class as it is more up to date with its graphic designs/ images and the children will visually find this more appealing in comparison to 'Bubblus'
Here is a link to my example below:
The only limitation I have found so far with this programme is that you are only allowed 25 free mindmaps but there is no one stopping you creating a new log in. From what I can see so far, you can only embedd it into your blog or wiki either as a link or export it as a PNG image but other than it, it's not a bad tool!
Let me know if you find out some wonderful other things!