3. Diamond Rio 500 Perhaps no area of the media and entertainment business has undergone more turmoil in the waning ... So dona#39;t expect them to replace cassette tapes soon. ... But so far only one so-called information appliance seems poised to make the jump: the iPhone from InfoGear ... Ita#39;s a $399 desktop phone with a large, 7.4-inch liquid crystal display (LCD) screen and a pop- out keyboard thatanbsp;...