<< Today, we're adding Gmail support to Google Sync for iPhone, iPod Touch and Windows Mobile devices.

Using Google Sync, you can now get your Gmail messages pushed directly to your phone. Having an over-the-air, always-on connection means that your inbox is up to date, no matter where you are or what you're doing. >>

http://googlemobile.blogspot.com/2009/09/google-sync-now-with-push-gmail-support.html

On the iPhone, you can only have 1 activesync Exchange account so this wouldn't work if you already had your work email setup and wanted to use Google Sync to get Push Gmail. :(

Still don't understand why gmail accounts under the Mail app on the iPhone don't automatically have Push ability.

I've just tried to enable this and it has broken the account. I've deleted it and tried to set it up again but to no avail – it says my details are incorrect – I've checked them countless times.

So beware – I now have no calendar events and no contacts until I can fix this.