I recently published an article on Alternatives to the Singleton Design Pattern on AspAlliance.com.  If you’re a fan of the Singleton pattern, I would encourage you to have a read and feel free to comment (here or there) if you agree or disagree with my position.  You can also learn more about the Singleton in the Patterns Library at Pluralsight.  Finally, if you haven’t read it, I definitely recommend checking out Jon Skeet’s coverage of the Singleton, as it provides several alternative implementations and demonstrates several weaknesses of the naïve implementation of the pattern.