Apple Insider takes a look at the Passbook support in Mountain Lion 10.8.2

f a Passbook .pkpass file is saved and opened on a system running OS X 10.8.2, users are shown the digital pass as it would appear on their iPhone. In the bottom right, a button that reads "Add to Passbook" allows users to push that pass to their iPhone, via iCloud.

Passbook support is also contained in Safari and Mail with OS X 10.8.2. If a user receives a Passbook attachment in Mountain Lion Mail, they are presented with a notification that reads "This message contains a Passbook pass."

Users can then click "View Pass" to see the card. From there, users can choose "Add to Passbook," which will add the pass to an iPhone or iPod touch using iCloud.

  First look: Passbook support in Mountain Lion 10.8.2