From Yuuguu Ltd.:
Yuuguu is a communications tool that enables instant messaging, screen sharing, and conference calling, among other features. Add your team members or clients via the "Find Contacts" button at the top of your contact window to build a network of people with which to collaborate. Click on a contact and choose "Chat" to open up an instant chat window for quick messaging and group chat. At the top of your chat window you will see the "Show" button. Click this to share your screen with the people in your chat window. When in screen share mode, the viewer is able to request control of your machine and is allowed only with your acceptance.
Every conversation is allocated it's own private global conference bridge. This is always displayed at the top of your conversation window. Everyone in your current conversation will be shown the same PIN number - so at any time you can all dial the number shown, enter the PIN number and be placed instantly into a voice conference. Each participant can change the dial in number shown by clicking on the underlined country name by the dial in number.
Yuuguu now offers integration with Skype.