Luminoodle reinvented what string lights can be, and two different models are 20% off today.
The Luminoodle Basecamp plugs into the wall or the power port in your car, and provides you with 20 feet of flexible light in 14 different colors. It works great as a permanently installed accent light, say on your patio, but you could easily throw it up between a couple of trees to illuminate an impromptu outdoor event, if you have a place to plug it in.
For a more portable option, check out the Luminoodle Plus. This one’s only 5' long, and only glows white, but it runs off USB, and includes a 4400mAH battery pack that can power it for about three hours. You can even ball it up and throw it into the included translucent bag to use it like a lantern.