Mind mapping software

[msa969]

I need a software for thought shower, spider diagram, brain storm etc. I think the software industry call it mind mapping software.
Does anybody know of freeware mind mapping software I can use at school?

Since it is at a school it is quit easy to get Admin to instal freeware.

Thank you in advance

[mjc]

http://en.wikipedia.org/wiki/Mind_map

There is a list, with links, near the bottom of the article...

[azzey]

Inspiration (http://www.inspiration.com/) is also good software. I believe there is a trial available (it is shareware), but it's fairly cheap to register.