I just LOVE the switch between flat and spherical view used by 360cam on http://www.360.tv/gallery.
Click on the 2 buttons right bottom of the player ;)
Good news this is done with Krpano, but it looks it will only work with a unique equirectangular file ( <image><sphere url="pano.jpg" /></image> ).
Could it be possible to achieve this effect with multiresolution tiles ?
That would be HUGE !!!