This is what I'm working on for local community resources -
http://doplaces.com The info is readily out there, and as you say there is info in lots of places... problem is some people don't really one solution especially if it isn't theirs.
For inspiration I googled around and looked at community search, event calendars, etc in the Portland area, sooo many variations, some good some not so good, some strictly limited in scope, other with specific goals that don't mesh with others.
It all sounds a lot easier to envision than achieve. My suggestion just find something you think you can do better and start eking out your niche.