New Web Site Helps Compare Gasoline Prices By MICHAEL RUBINKAM     PHILADELPHIA (AP) -- Hate it when you fill 'er up and, five minutes later, spot another station selling gas for a nickel a gallon cheaper?    Jason Toews, a 30-year-old computer programmer from the Minneapolis suburbs, hated it even more when he couldn't find an easy way to shop around.    "I even tried calling up some of the stations to find out what their prices are and they usually didn't like to tell you over the phone," he said...