There is a very cool microsoft research project called PEX which automates parameterized unit tests to help hunt down and kill bugs in your code and could make you more efficient in order of magnitudes. Do yourself a favor and check it out:
http://research.microsoft.com/Pex/
One problem though... it is not available to the general public. If this is something you thing you could benefit from (or if you feel like doing something nice for me... because I could definately benefit from it), contact the people on the project (http://research.microsoft.com/Pex/people.aspx).
If enough of us request it, maybe we could get them to allow us to work with this tool to help us write better code.