After lots of searching, I struggled to figure out how to disable mobile browsers (i.e. Android/iPhone browsers) zoom function so I thought I would share it since its important for developing games and more advanced mobile sites.
I can confirm that the following works on the Android and iPhone browser. Unfortunately though it does not work on HTC's custom browser that they have put on most of their Android devices. I have contacted them about this and they informed me that it is impossible. Not happy HTC.
<meta content='True' name='HandheldFriendly' /> <meta content='width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;' name='viewport' /> <meta name="viewport" content="width=device-width" />