although the magic mouse has solved the problem with the far too easily clogged up trackball on its predecessor, by simply doing away with this ‘3rd button’ it has created another major problem: how can you pan in applications such as ArchiCAD, Photoshop, etc.?
there is actually a really simple solution, install ‘MagicPrefs‘ (free) and not only do you get your center button back for panning around, but you can even set the mouse to recognise gestures!
however, if you do not want to tinker around just use the ‘graphics, 3d, CAD, modeling’ preset and you are ready to go.