If you’re worried about losing an iPad or iPhone, you can greatly assist the chances of getting the iOS device returned to you by setting a custom “If Found” message as the lock screens wallpaper. This only takes a minute or two to set up:
Use a drawing app (Paper for iPad is free and popular right now) to write out a simple “If Found” message, include a name, phone number, email address, and physical address for best results. When finished, save that image to the Photos Library.
Open the image from Photos app, tap the arrow box in the upper right corner, and select “Use as Wallpaper” then tap “Set Lock Screen”
Be sure to situate the image so that the message is always visible regardless of device orientation, this can be tricky to get perfect, but using a more squared “if found” image fits well.
Combine this tip with a secure lock screen passcode and Find My iPad/iPhone (configured within iCloud set up) to provide some added security and to further improve chances of tracking down a lost or stolen iOS device.
Mac users can set a similar lock/login screen message in OS X as well, though Lion or newer is required and it’s slightly less obvious than the wallpaper method.