Liberians may greet one another with a particular handshake that involved grasping the middle finger of the other person's right hand between one's thumb and third finger and bringing it up rapidly with a snapping.
This cutoms originated in the days of slavery when a slave owner might break the finger of his slave's hand to indicate his slave's captivity. When the freed slaves began to colonize Liberia, they began this ritualistic greeting as an indication of their freedom.
Read, before going: A wonderful -- if dated -- description of Liberia can be found in Graham Greene's 'Journey without Maps'. This is an account of an overland trip across the country in 1935. The atmosphere of the country it creates - particularly when dealing with the mysterious interior jungle aree a valuable and entertaining introduction for anyone planning to visit the country.