First, thank you to everyone who attended the webcast last week on ASP.NET 2.0 Web Parts. During the webcast there were some great questions and I had a fun time doing it. Below are the related links:
Also, the example with the UpdatePanel was a little dry. As a result, the demo now includes a Yahoo News Web Part that uses an UpdatePanel to refresh the UI dynamically. Below is a snapshot:

Lastly, included within the demo; is an example of the TextBoxWatermark control from the Ajax Control Toolkit and a simple client-centric example.
References and related articles: