Developers that use unit testing are familiar with Resharper and his plugin for Unit Testing.
For those that like me, don't have a great pc hardware (Pentium 4, 3ghz, 1GB ram) the Resharper can be really slow, and affect the performance of pc. That's why i use TestDriven.NET
TestDriven.NET is a freeware license tool (there are others licenses for this product) that gives us the possibility to run unit tests with this plugin, that's integrated with Visual Studio.
You can check some screenshots here: http://www.testdriven.net/Screenshots.aspx
It's compatible with: NUnit, MbUnit, MSTest, NCover, Reflector, TypeMock, dotTrace and MSBee.
More information and free download here: http://www.testdriven.net