Most glow in the dark products are made from zinc sulfide doped with tiny amounts of copper. This compound is inexpensive, but the glow does not last long.
A very long lasting phosphorescent material has recently been discovered. It glows bright green for over 12 hours (all night long) after charging in the afternoon sun for an hour or two. It lasts so long, and glows so brightly, it has been named Kryptonite, after the glowing green mineral in the Superman comics and movies.
You can charge this stuff up by setting it next to a lamp for a while, then turn off the lamp and have a free night-light, or read Superman comics with it under the covers.
The material is made of strontium magnesium aluminate, doped with the rare earth lanthanides europium and dysprosium. No evil genius should be without a vial of this in his pocket!
Imagine sprinkling sand made from Kryptonite onto sidewalks before the concrete hardens. Now you won't need street lights. How many other uses can you think of?