TestDriven.NET just keeps getting better and better
If you haven't checked out the free Visual Studio add-in for unit testing, TestDriven.NET in a while, do yourself a favor. Jamie Cansdale and Grant Drake have been busy.
It now includes a code coverage reporting tool that is quite slick. http://weblogs.asp.net/nunitaddin/archive/2006/03/15/440266.aspx