After seeing this marvelous bit of hackery I've subscribed to blog. Anyone with that level of curiosity must certainly have other interesting knowledge to share.
I did receive a few error messages when editing my profile. They just said that the owner of the site had received a notification and to check product.log It happened when I was attempting to edit my rate.
After a few tries it worked. I think it might have been related to entering too much text in the rate field, because when I shortened my explanation it worked just fine.
Its a text based search and I'm working on some simple query expansion to resolve SF / Bay Area / San Francisco type queries as the same. There are still a few open questions for implementing proximity search ...
A simple approach is to just geocode all the locations to a lat/lon and do a proximity search using WGS84. If someone has a location entry in their profile that fails geocoding, put up a warning the next time they login telling them that their location was not resolved and they should update it.
Don't worry about queries like "SF" or "Bay area"... if it's not good enough for the geocoder to resolve the location, just return an error message.
I thought this would be a better way for us HN consultants to connect, but I'm happy to remove you from the DB if you prefer. My email is in my profile.
note that I've addressed most of the issue in the original post but let me know if you have any other feedback.