Never forget your Apple 30-pin or Lightning charge/sync cable, as long as you have your keys. The Bluelounge Kii is a key style USB to 30-pin or Lightning charge and sync cable. Strap the Bluelounge Kii on your key ring and you are good to go.
The Kii has a full size USB port on one end and the Apple connector on the other. The 30-pin version costs $19.95 while the Lightning version costs $39.95 (ouch).