The Sun used to be fun, but now it seems to be a glowing orb of evil, casting down menacing rays of cancer and wrinkled skin. You can fight the light by slathering on sunscreen, of course, but now there’s another weapon at your disposal; Oregon’s Scientific UV Sensor (19.99). The timer recommends exposure time based on how harmful the UV rays are at the moment, along with which kind of skin you have and your sunscreen’s level of ...