A while back I reviewed some software called Midgard, and they included a 'demo' called TownPortal. I always had visions of doing that for the city I lived in.
http://www.midgard-project.org/
Also, local rentals, seasonal rentals, realtors, etc. Basically, become the information authority for the city.
A client of mine years and years ago had a series of sites:
http://rockvillepike.net/ is one of them -- I can see it hasn't advanced much.
The one thing I have looked for is a CMS that had a decent classified ads and auction package with a message board. Perhaps a calendar as well. Then you could have people putting in local events. Link to a matchmaker/personals service.
Get with the realtors, and they can post the Open Houses notifications. Quite a few opportunities.
I only wish I had more free time.
