It looks like Daniel Schaller has re-launched the old GeoURL service. I say ‘re-launched’ but to be accurate he didn’t launch it in the first place. That was Joshua Schachter, who is extremely busy with the very wonderful del.icio.us at the moment.
The service seems to be off to a slow start; just 108 sign-ups in a month. I’ve signed up to the new service now and updated my links in the left column. If you want to do the same be aware that the find my neighbours url has a slightly different format. You now have to provide your lat and long in the URL rather than just your registered site name. Here is mine: find my neighbours. I’ve set the distance quite high for now as there are so few on it.
Update: Daniel has implemented the old way of querying; by using your site url. See his comment.