So, I had this lucite rod sitting around, just begging to become a project. I've always thought that glowing lucite rods were cool, and this one is 1.5" in diameter, so I thought, "Well, just drill a hole in one end, and shove one of those little flashlights into the hole."
Well, those flashlights are still more than a half inch in diameter, and they cost a bunch, so I nixed that idea. On the other hand, I'd been playing around with some AAAA (yes, quadruple A) batteries. If you peel off their plastic wrapping, and snap off the extra metal nipple, both contacts are at one end. I figured, if I drilled a small hole at the bottom to hold the bulb, I could then just shove the battery down into the hole, and the contacts would press against the bulb leads.
It turned out to be a little more complex than that, but not by much.
In the dark, it really lights up well. The above image shows how the end with the bulb is really bright, but the opposite end is visibly illuminated.
The battery only lasts a couple of hours, but I found a cheaper source of the batteries. It turns out that the cell at the heart of a AAAA battery is exactly the same as the six cells in a 9V battery.
If you've gotten everything lined up correctly, the bulb will light, and now you can start doing twirling routines in he dark.