Check the very, very bottom of this blog for a new feature, recommended by my friend Glen. You stick in on your blog, and it shows where people have come from in the world, with circles proportional to the number of visitors. You can get it free at http://www.clustrmaps.com/. Click the map, and it will show you an expanded version.
(What's the revenue model? It cleverly posts ads for websites related to the topic of your blog.)
While it collects circles over the next few days, I am taking a writing break in honor of Independence Day. Please continue to submit comments, but I may be a bit slower about posting them for several days.
[Addendum on July 31. I have disconnected this link. After a while, it really doesn't show much new.]