NEW YORK (Reuters) - Regular gasoline pump prices in the United States may average as high as $2.50 by Memorial Day, shattering the records as futures prices climb to new peaks, analysts said on Friday. U.S. retail gasoline is already running above $2.15 a gallon, well beyond last spring's peak of $2.05, according to government and industry surveys. "Surging NYMEX futures are certainly an upward pressure on prices at the pump, so I would certainly expect to see retail prices move up sharply over the next few weeks," said Tim Evans, analyst with IFR Energy Services. Gasoline futures on the...