I love diffusers, but I don't use them as much as I should because it sometimes feels like a hassle to fill them up, clean them, and find a spot for them. That's why I'm excited about The Pluggy ($20), a new USB-powered plug-in essential oil diffuser you can use with just the bottle and no water. Screw in your oil of choice, plug it in, and let the therapeutic aromas improve your health.