This afternoon, a friend of mine posted a link to the HTML5 Readiness visualization. I am a bit smitten with this tool - for a number of reasons. It is useful, usable, and compelling. First off, it effectively communicates which browsers are capable of which "new world features." You can use this to plan which features to use when developing your site because it's easy to check if a feature is supported. In addition, it took all of 2 seconds to understand the tool and how it works, which is the very definition of compelling as I see it.
Check it out. It's really cool and you'll like it, if this sort of thing is important to you. I guarantee it.