(defamation blah by Quickseller snipped...)
If you are going to transact with cash in the mail, then one party (or both) needs to have huge amounts of trust. Even if you video tape the packaging/opening of an envelope, there would be nothing to stop one party from tampering with the envelope before/after the video stops.
I would have thought it would be pretty obvious to most persons that used paper wallets what the solution to suggestions of tampering would be...
http://www.tamperevident.com.au/As discussed on the SexCoin Forum's paper wallet's thread as well as here.
Do try to keep up Quick
sandseller