Have you ever used Live? As a stock holder I hope so
, when you register a Live ID or when you change your Live account password you are given a Password Quality Feedback Indicator, a couple friends of mine worked on this, feedback indicators are not new, but the Live one is the first one I had a chance to hear 1st hand about the design process used and how well such systems fair with users in usability tests.
In any event I ran across a blog post/cartoon on password validation that reminded me of this and made me chuckle, as such I decided it was worth sharing with you.