Mayor Michael Bloomberg announced today an odd-even gas rationing plan will go into effect tomorrow morning at 6 a.m. Drivers in the city who have license plates that end in an odd number or a letter will be able to buy gas only on odd-numbered days. Those with license plates ending in an even number or the number zero will be able to buy gas only on even-numbered days. Bloomberg says he thinks this is the best way to keep gas lines shorter and help stations stay open longer. All commercial, emergency, para-transit vehicles, buses, medical doctor plates and any vehicles licensed by the Taxi Limousine Commission are exempt.