Hi ksouthworth,
Yes I use a seperate test database, I don't like to use a fake repository as this isn't really testing the application through the layers i.e. I am not testing agains't a real database.
I am working on the source code for my next book and its up on codeplex
http://agilenet.codeplex.com/. If you take a look at this project in a couple of weeks you will see how I use a test database and clean it before each feature.
Cheers
Scott