Ever since the iPhone was given Exchange support for Calendars, one of the first things I looked for was how to get my Google Calendar on my phone. I soon learned about NuevaSync, a free service that allows you to link (via Push) your Google calendar and contacts to your iPhone. It's pretty straight-forward and secure. However, up until today calendar if you had multiple calendars you weren't able to differentiate between then since the service didn't provided color identifications. No longer is this a problem!

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