IP Atlas
IP-Atlas takes an IP, refers to NetGeo and then plots the location on a map of the world. With a few mods, you could give it a list of last 10 visitors’ IPs to see where people are coming from. Better yet, snap a picture of visits every 10 minutes (where each snapshot encompasses a sliding window of visits over the last 30 minutes if your site is low traffic) and stick them together in an animation. Then you could see if the visits are geographically random and time independent, or if you can see a higher frequency of visits visible in a band that sweeps westward over the globe as people sleep/wake.