It's too bad they don't make this gizmo for our car keys as well. Kensington's BungeeAir keyfob wirelessly monitors how far you are from your iPhone and lets you know when you've gone too far. Similar to proximity technologies used to protect healthcare data from prying eyes, this gadget not only lets you know when you're leaving your iPhone behind, but also locks the iPhone's screen down so that its data can't be compromised.
Wait, there's more. More power that is. The BungeeAir includes a protective case for the iPhone that, with its built-in battery, gives you an extra four hours of battery life between power pitstops.