The good people at 4 Guys From Rolla have provided a very interesting article on a program for .NET developers called FxCop.
FxCop is a program that will help enforce rules on your code, based on the "Microsoft .NET Framework Design Guidelines". According to 4 Guys, FxCop reads the meta-data of an assembly, instead of trying to analyze your source code. By analyzing the assembly through reflection, FxCop gains a better understanding of what your code is doing.
Any tool that will help enforce best practices is definitely worth a look. Although I haven't spent much time with this tool, what I've seen so far is very promising.