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.
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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!