Wow... that was a great webcast! As promised...Here's the demo code that I built during the presentation. Feel free to download it and play around with it.
Also, don't forget to check out http://www.asp.net and go through their tutorial on how to do the communications between web parts. It's great.
I'll get back to you (Venkat) on your question about using Web Parts in the Master Page and consuming them on the Content Page.
(You can see all the web casts in the ASP.NET Soup to Nuts series at http://www.aspsouptonuts.com.)