Jonah over at MAKE points out that you can actually make your Arduino a lot greener. How? Use a Solio with an external USB cable to provide your favorite microcontroller with power. If you don’t know what a Solio is, it’s essentially a small solar powered gadget charger. While this isn’t exactly a breathtaking hack or anything like that, it’s a new way of using a Solio and an alternative way to power your Arduino come this Halloween!