Next best seems to be the Play.com submission over a month ago at £17.99. Yes, yes, maybe something that should have been included on day 1 but it wasn't and personally I am quite keen to play Sports resort and the like...
Wii MotionPlus tracks players' movements in finer detail and with greater accuracy than ever before when used with specially designed games
Builds upon the innovative wireless function of the motion-sensing Wii Remote controller
Replicates the slightest twist of the wrist or turn of the body exactly on the TV screen, allowing users to become even more immersed in Wii game play
Wii MotionPlus is designed for easy attachment to the Wii Remote controller.