The inclusion of Reminders in OS X Mountain Lion is one of its most useful aspects for many users, including myself. The ability to sync reminders from my iPhone to my Mac is absolutely fantastic.
As nice as Reminders is, however, there’s an easy way to make it even more useful – by importing and exporting reminders between calendar apps and Reminders for Mac! Better yet, it’s extremely easy to do!
To export, just click File > Export from the menu bar. You can then import the reminders (as an iCal ICS file) into Google Calendar or another calendar app. This also works the other way – you can import items into Reminders as well!