Posting twice in one day has to be some sort of a record, but today I found the coolest free tool for sharing your desktop and holding a video conference and couldn't resist. I have two screens and tried sharing with myself. It seems to work reasonably fast and smoothly.
There is no registration and it can handle up to 250 people together in one meeting. You can also have a Join.Me icon on your desktop if you like to set up meetings on the fly. The person who calls the meeting uses the Share Button to get the meeting code. One the others in the group receive the code, they can join the meeting. Control can be passed around. If you're showing a video, the sound is not broadcast from your computer, so you'll have to hold the phone up to the computer speaker.
Participants can communicate via phone or chat box. Join.me provides a free conference line, but it's not toll free so you may be charged for a call, but you can use your own conference number by changing the audio setting.
Finally there's a mobile viewer for iPhone and iPad now available and there'll soon be one for the android phones. From Digital Inspiration: "the apps are free, incredibly easy to use and also supports text chat so you may not just watch the presenter's screen while on the go but also interact with the meeting participants."