An AttitudeAdjustmentTool. Primary training tool of the ExtremeProgrammingMaster. Related to the TwoByFour commonly used to train mules.
Snoopy said that this tends to give one a distorted view of the press!
Not sure if it's common usage, but I've seen the verb "fwap" used to describe use of this particular tool.
Different from a ClueStick in that it does not necessarily bring enlightenment.
See: ZenSlap, BrutalSarcasm, ClueByFour, ClueStick