My e-mail says...
I just bought a cheap mapping GPS and am programming in some local airports. What's the best online free source of coordinates for US airports?
I don't know. I always use aviation GPSes with commercial databases. But I can be lazy with this blog entry and help him out all in a few paragraphs. Because I'm sure one of you knows. He says he has to do manual data entry, so he's not looking for any particular format. Sounds pretty primitive!
My correspondent assures me that the GPS is just a toy for him and that his primary navigation will be based on current legal publications.