Get everybody on the same page, when they're not in the same room, instantly. Review documents and designs. Train staff. Demo products or just show off. join.me is a ridiculously simple screen sharing tool for meetings on the fly.
This is an amazing site that allows you to share your screen live with up to 250 viewers for free. You can even view the screencast on ipad/iPhone and Android phones. Perhaps most exciting of all is that you can use the site to control the viewed computer remotely, a useful feature for fixing any computer problems from afar. You need to download a small file to start sharing.
http://ictmagic.wikispaces.com/ICT+%26+Web+Tools