Desktop Sharing ... more than 100 people

http://www.online-tech-tips.com/cool-websites/5-free-remote-desktop-sharing-and-screen-sharing-solutions/
I would add also real vnc and ultra vnc.
www.uvnc.com
www.realvnc.com

thanks davorin, but my problem is that we are doing free children classes, and you know they join like any thing, we've invited only 10 people ... but now it become almost 100 kids ... please help what should we do, what are our best options, I've bought gotomeeting too, but they are allowing only 16 users ... :-(

Please help/suggest/guide, what are our options, we have our own servers (linux), if we need to install/configure some thing on our own servers ... that is doable too, but need some solution, as the next schedule class is on our head ...

Thanks in advance for help.
Best regards,
EL

Hi,
I think I had a little bit misunderstood your needs.
You probably need a program that would allow you to (web)cast your desktop to multiple PC's.
Something similar I have found here:
http://www.classroomspy.com/classroomspy_pro.htm
but, I don't know the program and how safe it is.
Are all computers on the same location?

I've checked this program, looks good for my local network, I don't know can I webcast my desktop to others too, who are outside of my network via internet ... please suggest, will this work or ... need some thing else, I bought gotomeeting too, but it is only limited to 16 users ... :-(

Please help/assist/guide ... thanks.

Thanks davorin ... but its all open and I can communicate within ourselves (intranet) ... but how to allow users from outside, and we just want to show our desktop ... no monitoring of any other computer, basically giving classes for free to kids ... and because it is free ... getting a lot of registration ... :-(

I think we'll be needing their IP address to add that computer ... right?

No, on your LAN (or intranet) you have private IP addresses. For connection to internet you probably use router. On external router port you have public IP address. You need to do port address translation (port forwarding). Every connection that will come to your external  public IP over TCP port 5444 should be forwarded to internal IP address of your broadcasting computer.

thanks