Mikogo is a free software for screen sharing and online meetings. Mikogo also offers Skype extra tool.

Mikogo allows to share your desktop up to 10 participants simultaneously. To start a meeting download the software and create a meeting. Now invite all your participants, you will be notified when the participants join your meeting. When they join they will immediately see your desktop. You can also switch presenters in the meeting, useful if collaborators wants to have a meeting. It also allows to transfer files between users.

Overall the app looks good and quite useful for sharing desktops and online meetings. Other tools which allow you to screen sharing and online meetings are Yakkle and Yugma