And besides that, the commercial airlines do courier postal packages & letters for high priority stuff. all the major courier services offer same day delivery

And besides that, the commercial airlines do courier postal packages & letters for high priority stuff. all the major courier services offer same day delivery across the US. I learned this when I flew from NC to CA and left my car keys in NC. I could have gotten them on the next plane to CA for about $300. It wasn't worth it.