You can draw just about anything on this glow-in-the-dark T-shirt
If you want to turn yourself into a walking billboard, you have several options. You could always use a wearable sandwich board sign, but those are clumsy and awkward. You could go with a Chalkboard Tee, but that's awfully low-tech. Or you could wear a Lüm T-shirt.
Currently in Kickstarter mode, Lüm is an apparel line made from light-sensitive glow-in-the-dark material that lets you scrawl messages across it. All you have to do is trace a message or drawing on it using an LED or laser light source—like a flashlight or a laser pointer—and whatever you scrawl will appear on the shirt...and glow in the dark. You can also hold a smartphone or tablet to it for a few seconds, and the onscreen image will transfer to the shirt.
I would've loved this when I was eight years old.
The on-shirt images glow for about 15 minutes, so you aren't stuck with what you drew. And you can aways go back and draw something new on your shirt.
We don't know much about Aamir Patel, the product's creator, or his track record, but if Lüm works as advertised, it looks like it'll be a fun novelty—if not particularly practical. The project has already surpassed its $10,000 funding goal, but if you want to pledge your support for Lüm, for still have 13 days to do so as of this writing. The Lüm Kickstarter page has additional videos and more on the manufacturing process for your viewing and reading enjoyment.