There is one interesting concept in F# language:
Object Expressions (F#)
http://msdn.microsoft.com/en-us/library/dd233237.aspx
Definition:
An object expression is an expression that creates a new instance of a dynamically created, anonymous object type that is based on an existing base type, interface, or set of interfaces.
I wonder, does something similar exist in C#? Or this stuff is only available in F# programming language?