A while back Psi-hoops came out with these amazing hoops that have LED lights in them. They are really beautiful. I wanted to purchase one, but was scared away by the $200 price tag. You can see a few videos of them in action here.
Recently, jeffkobi posted a how-to on making your own LED Hula Hoop over at instructables. He said he spent about $15 in materials. Yeah!
To learn more about the hooping phenomenon, go to hooping.org.