I've just been looking at a new product called "DimDim" (www.dimdim.com), for hosting web meetings. I haven't done much with it yet, but it looks very interesting. I'm going to run through a few of the highlights right now, and I'll fill in some details as I explore it.
Basically what DimDim provides is a way to host web meetings with video and audio of the meeting host/provider, shared presentation of a whiteboard, the host's desktop and/or PDF files and PowerPoint presentations, public and private chat between participants, and apparently optional audio from meeting participants. All this with no software download or installation by participants, and only a browser plug-in needed for the presenter! That's pretty impressive, if it works.
There are several versions - "Free", which will allow you to host up to 20 people in a meeting room, "Pro", which will allow up to 100 people in a room, with charges in steps based on the maximum number of participants allowed, and "Enterprise", which sounds like it will allow more participants than any rational amount of internet bandwidth would support. I have just been trying the "Free" version.
The way it works is that the meeting host/presenter signs up for a DimDim account (no charge for this), and then sets up a meeting, either to start immediately or scheduled for some later time. A list of participants is given, with email addresses, and an email is sent to each of them with a link to enter the meeting.
The first time a host starts a meeting, a browser plugin has to be downloaded and installed on their system. Once that is done, the meeting room is opened, and the host waits for participants to arrive. The host is broadcasting video and audio to all participants, and can select whether to send/share their desktop, a whiteboard, and PDF or PPT files. There is a public chat box on one side of the screen, and a list of participants on the other, with private chat buttons and such for each participant. I tried all the basics out, and it does seem to work - connection, participant entry, sending video and audio from the host, receiving by the participants, sharing desktop and whiteboard.
I will investigate and test, and report more later.