In the spur of the moment I signed up on a few location-aware social networks.  I am not sure how useful they will be to me when all of my friends who are on it live on the west coast and I live on the east coast.  Facebook becoming more location-aware, as the rumors indicate, might solve that problem.  However, at this time of year, my locations are pretty constrained: home, work, kids' schools, coffee shop, grocery store, soccer practice.  Me thinks I am not the target demographic.