I got around to adding GeoURL coordinates to my homepage and a link which displays websites within 50 miles of my website. It feels kind of weird thinking of a website inhabiting an actual location in the real world...but of course it does.
If you'd like to try it out all you have to do is add your some stuff to the HEAD element in your HTML.
<head>...then submit your URL to GeoURL, and they add it to their repository in 5 minutes (seemed instantaneous to me).
<meta name="ICBM" content="42.24591,-88.31638">
<meta name="DC.title" content="Inkdroid">
<title>Welcome to Ink</title>
</head>
You can control the radius with simple params:
You get the picture.