Big fan of geos here, but unaware of any specific forums or resources. Most of my serious successes in geo domains comes from selling them to area professionals; eg. I hand-regged a ton of Lake Tahoe-area kw domains, did some testing and on the better ones built out basic content or UGC sites, with each pointing to a relo lead capture form. Once they were up they were essentially self-maintaining, and 90 days worth of traffic and leads was sufficient to sell off the parcel to a real estate company in that area. Did something similar with an insurance agent in Florida on auto and life leads ... the pitch to these end users is pretty simple inasmuch as what they are buying doesn't cost much more than a Yellow Pages feature or prominent ad in their local newspaper, but unlike those advertising services they are laser-targeted and already bringing in leads.
Lawyers, real estate, "opt-in" doctors like plastic surgeons and lasik, insurance, all great end user businesses for geolocal domains.
Frank