Which layer of the application should contain DTO implementation

Question

Lately I\'ve been hearing a lot about DTOs and how useful they are but I can\'t find a good example of using it in ASP.NET context.

Let\'s say I use three tier architect

Answer 1

I use a project named Shared for such purposes, spesifically to share object with all layers. Regardless of the name, it should be visible by all layers.