Hate unlocking your Android smartphone so much that even Face Unlock or Skip feels like too much of a hassle? Motorola just came to your rescue. The company has partnered with VivaLnk to launch the previously teased Digital Tattoo, an NFC-based skin tag that unlocks your phone (currently limited to the Moto X) with a quick tap. The tattoo can stay on your body for up to five days, and it should survive abuses like showers and sweat-laden runs. It's a clever approach that might be appealing if you're fed up with PIN codes and patterns, although the back-of-a-napkin math suggests that you're paying a lot just to save a couple of seconds when checking your email. VivaLnk is asking $10 for packs of 10 tattoos, or enough to last 50 days -- you'll have to spend $80 to get through a whole year. It could be useful for those busy days when you're constantly waking up your handset, but you might be better off rolling that money into a Moto 360 or your next big phone upgrade.