Billed as a "display and carry case," Griffin's new Standle for iPad ($50) immediately raised the excitement meter when we first saw photos this week, though the reality of the product is a little more complex. The glossy black hard plastic case is a two-piece design with a snap-on front bezel and back shell, turning the iPad into a boxy handle-equipped, carry-it-anywhere screen with twin video stands. One pops out to hold the iPad in portrait mode,…