Google's improved how its calendar and email services interact with Windows Phones running the Mango update. Users can now cram up to 25 different calendars into the Metro OS's built-in calendar app. The setup's not exactly seamless; you need to navigate your Windows Phone to the Google Sync page, login and check the boxes found there. While testing on our phones, although one device was able to immediately sync, the other couldn't pick up on our multiple calendars. We had to delete and re-assign our Google account to the phone in order to get it
