Anonymous Types - Are there any distingushing characteristics?

Question

Is there anything to use, to determine if a type is actually a anonymous type? For example an interface, etc?

The goal is to create something like the following...

Answer 1

For the purposes of extension methods there is no way to distinguish an anonymous type. Extension methods work by specifying a method for a compile time nameable type. Anonymous types are un-namable and therefore not visible at compile time. This makes them incompatible with extension methods.