can I access any system settings?

No, You can not do this on iOS neither in AIR nor in Native App.

On Android you cant do this with AIR currently, but in future releses there will be a functionality which can let you achieve the same.

Thanks,

Saumitra Bhave

AIR iOS

I dont think this is possible in iOS with the API provided by Apple so AIR won't support it because it's just impossible in one of the supported OS... (you would have to jailbreak your iPhone and use a private API).

It might be possible to bypass AIR on Android to do it. Search on google about : Extending AIR for Android. Using a socket, you should be able to call the native android activity that run your AIR application (or a service started when you launch your app). I'm using this trick to send a PDF rendered in AS3 (and saved to the SD card) to PrinterShare when the user press a button in my AIR app. You will then have to hide this button on iOS (you can check what OS the app is running on in flash.capabilities.

var os:String = flash.system.Capabilities.os.substr(0, 3);
        if (os == "IOS") {
          btn.visible = false;
        }