Geo Neighborly
Sadly, GeoURL has been "down for renovations" and unavailable a long time.
Today I found a similar site that also does geographical proximity searches and uses the GeoURL-compliant ICBM META tags to recognize web site location: A2B. They are actively adding features. I found notice about some recent additions on the forum. Using A2B, I was able to re-add a "[What's] Nearby" link to this blog, just as I used to have one using GeoURL.