Microsoft SharedView is a collaboration tool that let you connect with up to 15 people in different locations and get your point across by showing them what's on your screen. Share, review, and update documents with multiple people in real time. A Windows Live ID (Passport, Hotmail, or MSN) is required to start sessions, but not to join sessions. New in version 1.0: added a web based join experience to make SharedView even easier.
Download: Microsoft SharedView