Evan Rodgers, The Verge:
Android users can take advantage of Google’s major services right out of the box, but setting Gmail, Google Contacts, and Google Calendar up on your iPhone isn’t quite so clear. It’s worth doing right, though: with a little elbow grease you can have a setup that’s every bit as good. It’ll let you use the new Gmail app, which is a big improvement over the iPhone’s standard mail app and most other third-party options, and you’ll also get a better, simpler calendar and contacts setup — goodbye, weird duplicated events and endless birthday notifications. Plus, we’d swear that our battery life got a lot better as soon as we left Exchange and turned to our new setup.
Google is cutting support for Google Sync at the end of January, which until recently was the only way to get push Gmail on your iOS devices. The Verge has been kind enough to write up how to keep getting instantaneous Gmail on your phone with the Gmail app, and keep your calendars and contacts in sync too.