Socially Speaking for 8.20.11:
Transparency lends itself to credibility.
If you mess up, admit it. If you don't know the answer to a question, admit it. If you're inexperienced, admit it. If you're willing to admit that you're not perfect, a work-in-progress, or open to suggestion, your audience is more likely to take you more seriously. You build your credibility and trustworthiness. The quickest way to lose credibility? Lie or attempt a cover up.
Be honest, be real, be transparent.