DesignMakeTeach had VSTE Conference members make pocket light sabers, and we fell in love with the idea. We have been handing out kits to make your own at a few conferences lately. They are very easy to make using an LED, a coin cell battery, a small (business card-sized) piece of tagboard, a straw, and small piece of double sided foam tape. The directions (in pictures) are below.
Our students also made these for various lessons (to explore electricity, to practice writing how-to paragraphs, and to sell in the makershop).