We love Apple’s new ad campaign for the iPod in Japan, which features the slogan “Hello iPod, Goodbye, MD”, a reference to Sony’s Mini Disc player. Sony really dropped the ball by letting Apple get a foothold in the portable audio market, with the Walkman they had practically owned the entire notion of carrying your music around with you for over two decades. Now Apple is close to shipping its millionth iPod, and Sony doesn’t even make a decent MP3 player. Of course, selling a million iPods in 20 months, while impressive, is not that huge a number when you realize that from 1979 to 1999 Sony managed to sell over 186 million Walkman cassette players, an average of over nine million a year. Apple still has a long way to go to before it’ll achieve the ubiquity that Sony once possessed.