So you would like to take your card tricks to the next level? Fireflies playing cards can help. These are LED light-up playing cards that can create amazing patterns in the dark. You get 4 individually-lit blocks that light up blue or green. You can recharge 4 Fireflies at the same time.
At the touch of a button these blocks light up to create amazing patterns as you move them between your fingers. This project is on Kickstarter right now. You can find out more here.