I am using Visitor Maps on three sites, and as soon as my paypal account stops being crap I will be giving a thank you donation.
I would love to see the ability to set an alias for an IP address. So known IPs, like friends houses, or the local library. Where an alias exists, it would be shown rather than the IP address. A further improvement on that idea would be that if the geo location changed substantially then it would flag up that the alias might be invalid.