I have just launched FSXDB.com. The goal is simple "Fast FSX Airport Search". I feel it's a great online resource
You can search Microsoft Flight Simulator X airport data by ICAO Code, Airport Name, Country, City, State, Runway Length, Elevation, Surface Type. Details page includes Runways, Com, VOR, NDB Frequencies and a Google Map.
BTW, Looking for developer for an FSX addon to integrate with this site. See details here.