You can set up the NUnit GUI application so that it re-runs the last test run after each build. If, like me, you have a dual screen setup, then you can do a build in Visual Studio on one screen and immediately see the test results in NUnit GUI on the other screen without having to do any task switching. I'm finding this a great time saver.
To set this up:
- Launch the NUnit GUI
- From the main menu select Tools | Options
- Select "Assembly Reload" from the left hand side
- Check the "Reload when test assembly changes" checkbox
- Check the "Re-run last tests run" checkbox