asterisk users - Mar 2005 - How could Asterisk help me on a Internet webcast speech!?

Hi All!

I have the folowing need:

We have a project in Brazil called Quinta Livre(Free Thursday) where we have 
one speech about some Open Source project, every last thursday of every 
month...

We want to make this presentation avaliable to more people, so we have to 
"broadcast" this presentation for everybody that wants to watch it
over the
Internet (in real time).

How could Asterisk help me on it!?

We could have some meetme accounts to give to the remote participants, so 
they could make some questions alive.

Something else!?

What about video!? Is there anybody here that use it before!?

I will apreciate any kind of help.

Thanks.

Denis Galv?o.