Chosen security now offers individual developers the opportunity to purchase code signing certificates for Adobe AIR applications.
The cost is a little high at around $199 for 1 year, but if you value your AIR development it could prove a worthwhile investment.
Having a trusted certificate makes distributing your AIR application to the general public a better experience. This is due to the fact that they can be assured that it’s from the correct developer and not someone else.
[via. Ryan Stewart