Beyond phones, watches, and activity tracking devices, a new ecosystem of functional and fashionable wearable technologies can easily, safely, and economically be designed, prototyped, and integrated directly on the body. In this paper, we present AlterNail, a fingernail form factor, ambient, low-power, stateful, wireless, dynamic display with onboard vibrational sensing. AlterNail integrates a batteryless design using inductive coupling with e-ink technology to enable both quick dynamic and long-term static fingernail based visual designs without the need for power. We also detail the use of simple vibrational signals to uniquely identify everyday objects as they are handled using AlterNails. The intentionally limited interactional functionality of AlterNails, coupled with the rich personal and dynamic expressive potential, combine to present a compelling range of opportunities for designers of new interactive wearable technologies. We detail a range of practical and playful applications using this technology.