Google is pretty well integrated into the iPhone, but one area where the Android OS has stood above this integration is with push Gmail. That has changed today with the launch of GPush (iTunes link), a Gmail push application for the iPhone available now for 99 cents. You can setup how you wish to be notified of your incoming Gmail, including through vibration, ringing or GPush icon display of unread messages. You will also receive a preview of incoming email with the sender's name and subject heading.
Hopefully, Apple doesn't nix this application like it did with the Google Voice apps. I am sure people will appreciate the capability provided by GPush and 99 cents is a great price for this functionality.