I love Christmas lights but I have a strong fear of rainy night electrocution so I never put them up. Now Frontgate has solar-powered string lights that charge in the winter sun and stay bright all night. Each 25' string includes 48 lights. They actually do need to be plugged into the solar collector, but just once, since they juice-up during the day on their own.

Even easier are the solar-powered garland and wreath, because they come pre-strung with lights and are cordless, powered by a solar-rechargeable 6v battery.
Prices from $49 - $95 at Frontgate.