Take a throwie (minus the magnet), hide it in the snow and watch it glow!
Ultrabright white LEDs
CR2032 coin cell bettery
Sellotape (electical tape would've been better but I didn't have any)
Step 1: Bend Your Legs
I found it better to bend the LED legs over so they didn't stick out the bottom and poke you in the hand when it's done.