Were you excited to try Spotify, only to be dismayed by the lack of native iPad support? Enter Rdio's latest update to its iOS app, now with gratuitous support for Cupertino's sweetheart. Just like its iPhone and iPod touch forebearer, slate fans can now stream music, cache songs, futz with playlists, all while being "social" with friends on the service. Like the company's other mobile apps (on iOS, Android or Blackberry) -- and its cross-Atlantic Swedish rival -- one has to spring for the pricier $9 monthly sub to unshackle from web-o
