How can I turn off the home screen preview of SMS/text messages?
You may not want to see the little preview of text messages that turn up on your home screen when a new text (SMS) message comes in. To turn this off, head to your iPhone settings and go to:
iOS 7 UPDATE: Turn off text message, SMS and iMessage previews in alerts, banners and Notification Center with the following setting:
You can also use this screen to set other parameters for alerts, including Alert Style.
OS 5 UPDATE: iOS 5 and later feature the Notification Center. To turn off the message preview follow these instructions:
Settings -> Notifications -> Messages -> Show Preview -> OFF
Settings -> Notification Center -> INCLUDE -> Messages -> ALERTS -> Show Preview -> OFF (gray switch, NOT green)
General -> Notifications -> Messages
Turning off 'Show Preview' will disable the text message preview on your iPhone.