Just to keep you updated: I installed a small GEOLOC world map image on the right-hand side, yesterday.
It's similar to the Hitmap, which I installed before, but also differentiates between users which are currently visiting the site ("online" users), which are shown as green points, and those who have visited the site in the past but are not currently online (the red points).
The service in its basic version is free, but if you are willing to pay for it you can have more features, e.g. detailed statistics, higher resolution maps and - probably the prettiest feature - a Flash-based map, with the online users shown as "blinking" dots (have a look at an example).
All in all pretty nice eye-candy, if you ask me.
Update: Hm, lots of people on the web seem to have the Flash version. I wonder if they really all pay for that, or if you can have that in the free version, too...