It's a statistics and traffic analyzing program installed on your computer that tracks your blog's traffic. It gives live counts of what's going on with your blog traffic, who is visiting what, where they are visiting from, a live interactive map showing you where your incoming visitors are arriving from, and so much information - it's amazing.
I don't get much out of watching blog traffic statistics, but this is live information, telling me who is doing what on my blog RIGHT now. I know this sounds like an ad, but it's not. I haven't had so much fun, as well as gathered information I can use from my blog traffic EVER. Very fun. Addictive. And helpful.
I'd love to see this added to WordPress.com, so if you would, too, vote for this and leave a comment.