Here’s a simple trick for those of you who find yourself always plugging in USB cables the wrong way on your first attempt: pay attention to the seam on the metal tip. Apartment Therapy writes,
Look closely on the metal tip and you’ll notice that there is a seam on one side of the connector. This seam denotes the contact side of the USB. In horizontal oriented USB ports the seam should face down. In vertical oriented USB ports the seam should face left. If you follow those rules, you’ll get your USB plugged in the right way, the first time, most of the time.
(via Apartment Therapy via Lifehacker)