Would it not just be a good idea to be able to favourite airports ( thread here - My favourites on the world map ) whether you have bought them or added free ones or just like a particular airport you could have them show up more.
Having say 2 or 3 other colours you could change the map marker to when you select it as a favourite and having a separate favourites list with them all in ( XP allows you to do this ) so you could just click on an airport in that list and it would go to it would be really useful.