One of the top features in C# 3.0 is Lambda expression. A Validation Library has been written , and published in Code Project Articles on this week. 

http://www.codeproject.com/KB/cs/ValidationUsingLambdas.aspx 

 You may find the below link useful for starting Lambda Expression.

http://www.developer.com/net/csharp/article.php/3598381 

The 2nd link is useful for comparing what we were doing before , and how we can improve our coding by using Lambda Expression.

The Syntax of Lambda Express is quite confusing but you will get used to it !