There's a new widget from the team at Amung.us: A mapping plug-in, maps.amung.us, that you can add to your site to show you where your site's visitors are coming from, updated in real time. At first it looks to be more fun than useful, but underneath the widget, Amung.us collects interesting stats. You need only to click through from the widget to check them out.
I have a love/hate relationship with widgets like this (see also Feedjit and MyBlogLog). Site managers who are thinking of adding these need to be aware that they can expose information about traffic and users to the general public. Some widgets can even expose readers' browsing behaviors to each other. In many cases, you can disable this, fortunately. For example, in maps.amung.us, you can change the part of the embed code that says, "&link=yes" to "&link=no". I've left the linking enabled here.
Maybe running a site with wide-open stats is what you want. But if it's not, you may need to forgo the eye candy.