Start a Dimdim Web Meeting.  

Dimdim is Open Source web meeting software.
With Dimdim you can show Presentations, Applications and Desktops to any other person over the internet. You can chat, show your webcam and talk with others in the meeting. As a Presenter only a browser plugin is needed while Attendees do not need to install anything.

To start a meeting, please supply an email and a display name for yourself. You will be able to invite others to the meeting from inside the meeting. You can also change the Meeting Key to something more relevant like "Sales Meeting" A meeting can also be scheduled for a future date. For this uncheck the "Start Now" option and please fill the relevant details.