This isn't a bad idea, but this wouldn't work in all situations.

For example, I am currently awaiting a 3rd party to write a web service that I will consume on my end. In the mean time, however, I would like to continue with development on my side. Having said all of this, the interface is most likely not ever going to exist on their side, so I'm forced to design the interface on my side.

So what I ended up doing was creating an interface, which defined the methods that my company, as well as the 3rd party, agreed upon. After that, I created a wrapper class, which implements my interface. Now, I simply create an object of type IMyInterface and initialize it using a factory method. As an added bonus, this will allow me to, for example, add a section to my web.config to be used for testing my web service at a later time, without having to recompile my code.

The idea is great, but I can agree with the previous comment, that it is not working in all situations!!!