This tool is useful for any online conference. Along with good video and sound quality, it has features to share screens, files and do many other things.. It is user friendly.. 

The reason why I am sharing this tool is that, many times people who give webminars use Microsoft Live tool and many people get confused using that s/w. So this tool can act as a savior, since it is quite User Friendly...

Here is the link of the website.