Oh No! There goes my motivation to write C# 3.0 Part 2
Following are short videos that explain all about C# 3.0 language features. I couldn't have explained it better than this:
C# 3.0 Language Enhancements in action
C# 3.0 LINQ in action
C# 3.0 XLinq in action
C# 3.0 DLinq in action
Anders Hejlsberg on LINQat Channel 9 - Channel 9
Chatting about LINQ and ADO.NET Entities - Channel 9
Source: TheServerSide.NET
Have fun!