I saw this task lamp on Instagram a few weeks ago. Against my better judgment—based on my previous experience ordering things from Instagram ads–I bought one. to my utter surprised, it actually arrived, isn't a piece of crap, and actually works the way it was advertised. It's USB powered, and actually can plug into a spare USB port on the back of your monitor.
I had good lighting in my room already, but there are times I don't want the room illumination on but still need a bit of extra light.
I can definitely recommend this.