Local Type Inference, Anonymous Types, and var
Bill Wagner explains a bit about C# 3.0's local type inference:
Of all the features in C# 3.0, local type inference is generating the most questions and misunderstanding. You know, ‘var’. The fact is local type inference is not as scary as it seems. In fact, you’re not losing strong typing. It’s a simple time saver that is actually necessary to support anonymous types.