So, if you haven't heard of the Onion Architecture, you wouldn't be alone. However, it's been around for a while under the name of Hexagonal Architecture, due solely to a graphic created when Alistair Cockburn first described it. It's also known as the Ports & Adapters Pattern. I highly recommend reading all of the links I've provided thus far however the Onion Architecture version of this pattern described by Jeffrey Palermo was the most understandable to me. I dug around for a while until I could find someone who implemented a sample project using the Onion Architecture and came across Matt Hidinger's presentation he did for the Chicago Code Camp last year. I destructed his sample project, documented it, and rebuilt it in a shape I felt I could teach and support. I then Templified it.
Here is that solution for Visual Studio 2010 on GitHub.
Here is the Templify template.
