It is, in a phrase, the single most interesting iPod speaker we've seen in the past year: iHome's iH15 ($60) starts out looking like a white plastic cube with silver accents on its three speaker drivers -- left and right active drivers, plus a front-mounted passive subwoofer -- but then you plug it in, and it makes magic: LED lighting inside enables all of its white surfaces to shift from orange to yellow to green, purple, blue, pink, and red. You…