Sometimes, we at TUAW get awesome tips from our readers -- this is proof. A certain, unnamed individual sent us some pictures of the latest build of the iPhone firmware showing .Mac push e-mail. The picture shows the main Settings page with a new button: "Fetch new data." When you click the button, you are taken to a list of your mail accounts, where you can choose between either "fetch" or "push."
According to Mr. Anonymous, while .Mac is offering push e-mail, you are currently not able to do contact or calendar syncing. You can see the iPhone screenshots in the gallery.