[TYPO3-english] Work groups

[* k-do *]

Hi,

I have to implement an intranet and I need work groups.
The philosophy of a work group is that at any time, a boss can create a work
group (from the frontend) indicating only the name of the group and the
users that have acces to it.

The ideal would be that authomaticly was created a structure of pages and
plugins offering tools to the group like: a discussion tool, a photo album,
video album, document uploading and downloading...

Is there any extension to do this? (I think not).
If not, how could I implement this?

Thank you