Two more screencasts have been published in the SharePoint for Developers screencast series. The series shows you how to use Visual Studio Extensions for Windows SharePoint Services (VSeWSS). The two new videos are:

The full screencast series is listed here

This series has been building up to an application for an end user to pause a video (rendered through a Silverlight media player) and capture annotations about the video at a particular time segment.

You can imagine that, in a media company, there very well could be additional actions taken when someone creates an annotation such as automatically sending a formatted email to an advertiser (“The text formatting at time 00:00:28.4500000 does not comply with our standards for broadcast”).

This is the real power and benefit of leveraging SharePoint as an application platform: we can incrementally add value to our solution without requiring us to build that functionality into the service.  In a traditional ASP.NET application, you would likely add new functionality in a business logic layer, requiring a change in database storage, changes to the UI to display the new functionality, and changes to the service layer to expose the data to remote consumers. 

With SharePoint, you could simply attach workflows to the content type, and any updates to the list via our web service will enjoy this new functionality without making any changes to the web service.  Or you might create a new content type and attach that to an existing list.