The Freemasons are famous for having a series of hand signals by means of which their members can identify each other wherever they may happen to be in the world. Now you too can pretend to be a Freemason. The secret is that, first, you need to memorize a series of hand signals all of which indicate different days of the week. The signals also require that you have pockets in your clothes (or that you have clothes on, period... so these won't work in a nudist colony):
Sunday sign: right hand in pocket of breeches, with thumb out, pointing to the left side.
Monday sign: left hand in left pocket, thumb out, pointing to the right side.
Tuesday sign: right hand in right waistcoat pocket, with thumb out, pointing left.
Wednesday sign: the reverse—left hand in left waistcoat pocket, with thumb out, pointing right.
Thursday sign: right hand in right coat pocket, with thumb and forefinger out, pointing downwards.
Friday sign: exactly opposite—for right, read left.
Saturday sign: putting the first three fingers of the right hand to that part of the right eyebrow next the ear, and so drawing it along till the 3rd finger touches the nose.
Note that you also need to be wearing a waistcoat! Now for the secret greeting. When a Brother meets a Brother he first has to give the signs of the two preceding days, and then the other Brother returns the 7th or Saturday sign. And that's it!
Unfortunately, these signs probably won't work today. The info comes from Secrets of the Freemasons Revealed by a Disgusted Brother
, published in 1759. According to Wikipedia
, the Freemasons periodically change their secret signals, in order to keep them secret. Nowadays, you may also be required to produce some kind of certificate, or paperwork, to prove your Freemason membership.