Nomad made waves last year with their ChargeKey, a little iPhone-to-USB cable that sits on your keychain so you're never without power, but it hasn't stopped there. Piggybacking on the successful foray into portable iPhone cables that you'll always have, the company is making carabiner and card versions.
NomadClip - $39
Do yourself a favor and slap one of these onto a backpack, beltloop, or suitcase. With the NomadClip, you can cover yourself for pretty much every possible contingency.
NomadCard - $29
If you've forgotten your keys and need to call your roommate to let you in, this will help you get that done if your phone's dead, which it probably is at 3 a.m. Slim enough to fit in your wallet, the NomadCard is your option if you don't like a bulky set of keys.
NomadKey - $29
The original ChargeKey is being reborn as the "NomadKey," and it's the option for someone who is too cool for carabiners and is afraid of getting a Costanza wallet. When choosing which one to go with, consider your lifestyle. Do you forget the wallet, backpack, or keys more often?