If you're interested, Adobe is presenting a free seminar about its Macromedia Breeze product helps you get web conferencing working right. The seminar is on June 1 at the Westin Atlanta North (the one at the Perimeter on Concourse Pkwy). Registration is required.
I wouldn't ordinarily post a notice about a non-Microsoft product but this is free and Macromedia products are usually fairly decent. I've got no experience with Breeze, but the concept of web presentations/web video conferencing intrigues me as a possible evolution in web-casting.