Have you ever used a DI container also known as Inversion of Control Container? one such as Unity or Structure Map?
If you have been curious to see how an IoC container works well you don’t have to keep wondering, because Daniel Cazzulino has some very nice videos about how to build your own DI Container with a nice set of features, and a rich and fluent interface using Test Driven Development (TDD) practices.
The link to his blog post is: screencast series on how to building a DI container using TDD
More info on Dependency injection.
IoC container help developers manage dependencies, hopefully someone will help USA manage its dependency in foreign oil :)