Ben Maurer’s answer to the Quora question about the safest way to send someone $1,000 in cash:

Get 10 new $100 bills. Cut them into thirds. Put all of the left sides in one envelope, right sides in another, and middles in a third. Send the envelopes separately.

It’s clever because the Department of the Treasury allows you to redeem damaged currency. It’s illegal because you aren’t supposed to willfully mutilate currency.

A Clever (and Technically Illegal) Way to Send Cash