Step 1: Everything You Need to Build a Tennis Can Lantern
1 empty plastic tennis ball container
1 tennis ball (or similarly sized ball)
1 LED touch light approximately 6.8 to 7 cm in diameter. These usually cost about $4 for a pack of three.
1 length of electrical tape (if necessary)
Step 2: Enlarging the Diameter of the Light Casing
Step 3: Insert the Light in the Top of the Can
Step 4: Basically You're Done
You can decorate the exterior of the can with stencils or colored paper or cellophane. I've decorated mine with a festive bar code sticker.
I haven't tried different colored balls, but I'm sure it would change the mood of the lamp.