A new epinephrine auto-injector is being developed called the Epinephrine Key.
http://www.tcbmedicaldevices.com/index.html (view a picture of the device here)
http://www.medicalnewstoday.com/articles/193773.php
A small epinephrine auto-injector that easily fits in the palm of one's hand, the Epinephrine Key attaches to any keychain. Just like regular keys, the Epinephrine Key is completely portable and always nearby, making it immediately available for emergency administration of epinephrine in the event of a severe allergic reaction.