Anglo Large Clawed Otter: Fixed. Editing airports (even those you're entered yourself) is currently not supported, but this may be added at some point in the future. For now, though, I've added more checking to ensure that only valid data is entered, and airport searches now highlight user-entered airports in pink.

SmilingBoy: The curves should look smoother now, since I bumped up the GC path plotting to one line every 500 mi, plus every 250mi for routes above 60 deg N/S, where the map projection causes the most distortion. Next, I need to figure out a way not to render all airports at high zoom levels, because this is the slowest part to draw...

Gnopps: Yes, this is on the to-do list, but it's a little harder than you might expect because I need to pull in the airline name from another database table, and I need to work out the logic to display just the airline code, not the entire name, but only if the user hasn't entered a flight code, except if the flight code doesn't have the airline code.

As for help, donations, adding OpenFlights to your sig, posting about it on other forums and/or nominating this thread for TalkMail are all welcome