Ken, a few years ago in my office, for April Fools me and another woman wrote a very official looking letter and sent it (without the knowledge of my boss) to half a dozen of our oil and gas partners, we hand-picked the stuffiest, most egotistical jerks, telling them that we were doing a naked men calendar for charity (like the older ladies did in England in 1990 to raise money for leukemia research. They ended up raising 500K, and it was later made into a movie) and that each of these guys had been suggested for "May" or "June" or whatever.
In those days we had some water well drilling operations in Hawaii, so we made up the name of some bogus charity, like Pacific Red Sea Slug Hibernation Research or some such nonsense. We said that we wanted them to come in for a photo shoot, and gave as the contact, one of the stuffier, squarer guys in our own office (without telling him).
We sent all these letters by courier, and of course, the guy in our office started getting calls right away. He came rushing out of his office all red-faced, "what in the world is going on?" "Are we doing some kind of calendar?" Our own boss heard about it in short order and thought it was so funny, he gave us a list of another dozen names to send the letter to. A lot of the guys who originally received the letter thought it was real, and they were all ready to come in and take it off, so to speak....morons. My girlfriend and I laughed until we cried....for days....