There have been many attempts to reduce or eliminate the sonic boom. For supersonic aircrafts such attempts fall into two categories: (1) aerodynamic minimums and (2) exotic configurations. In the first category, changes in entropy and the Bernoulli constant are neglected, and equivalent body shapes required to minimize the overpressure, the shock pressure rise, and the impulse are deduced. These results include the beneficial effects of atmospheric stratification. In the second category, the effective length of the aircraft is increased by modifying the Bernoulli constant a significant fraction of the flow past the aircraft. A figure of merit is introduced which makes it possible to judge the effectiveness of such schemes. Finally, the sonic boom reductions that can be achieved by hypersonic flight at high altitudes are summarized.