There's a webcast on that very topic tomorrow at 9:00 AM PST. It's a great chance to get more information on using this component in your applications to provide streamlined and performant data access code. Per the webcast description:
“The Data Access Application Block is a .NET component that contains optimized data access code that will help you call stored procedures and issue SQL text commands against a SQL Server database. The documentation provides guidelines for implementing an ADO.NET-based data access layer in a multi-tiered .NET application. It focuses on a range of common data access tasks and scenarios and presents guidance to help you choose the most appropriate approaches and techniques. This guide encapsulates performance and resource management best practices and can easily be used as a building block in your own .NET application. If you use it, you will reduce the amount of custom code you need to create, test, and maintain. We'll explore how to leverage this application block in this webcast.”