If you need to send someone cash quick, I did this and it worked great. Now I joke all the time with my Fedex guy "is that my bundle of cash today?"
This is information that someone passed on to me and it worked for me, so I thought I would pass it on to the masses. The first thing you need to do is go to your local fed ex shipper and pick up an envelope or a small box depending on how much you plan on sending.
Now I was told to take the cash you are sending and wrap it in aluminum foil. I wrapped the cash I sent in several layers of foil as I did not want a fedex person to know what was inside for fear it might get "lost" in shipping.
After you wrap it in the foil insert it in the envelope or package. I added some paper towels to make sure the package did not feel like a bundle of cash. Then I brought it to a fedex station and sent it next day.