I ran across this brand tag page from Seth Godin's blog. Basically it allows you to vote on whatever you think a company's logo represents. So a picture of crest may come up and you have to type in the first thing that pops in your head (lets say clean teeth). Then you can check what some of the common answers are by clicking through the list at the top of the page (they should make this into a family feud game... I would be all over it).
It all comes back to Al Reis's 22 Immutable Laws of Marketing of making sure your brand has a focus.