Glowsticking is a dance form where glowsticks, led-products and other related glowproducts are used. The roots of glowsticking are in electronic music scene: in the beginning it appeared in parties used while dancing, but becoming more popular it has diverged from rave- and electronica-scenes.
The purpose of glowsticking is to create a spectacular light show using different kind of glowproducts. The term glowsticking is an upper term for two different trends, glowstringing and freehand. Refering to the word glowstringing, lots of different kinds of strings are used, for example, whereas in freehand glowproducts are hold in hands and the use of other tools is avoided.
Glowsticking is a very cheap hobby to start: all you need is few glowsticks and if talking about glowstringing, a little bit of string, for example shoelaces. When you become more advanced, it is easy to add more music and other elements. With different kind of led-lights glowsticking can be made to look very spectacular: you can change the flashing phase of the led-light to make it look certan way to the outsider. For example a fast phased flash makes some sort of dots in the air, when a slower phased flashing led-light will make strokes with small breaks in the air. You can figure out the best glowsticks and led-lights for you by trying them out yourself.
More information about glowsticking can be found at Glowsticking.com, which is a website for people practising glowsticking. From the site you can find complete instructions of how to start glowsticking, different kind of tutorials, videos, pictures and active discussion forums. You can also find more information about it on its English Wikipedia article.
At glowstringing strings are used as tools with dancing. Video above will show you very well what glowstringing - and glowsticking - is about. Very showy moves can be done especially with glowstringing and that's the whole point of it. Glowstringing requires lots of room, so you can't usually see it at clubs or raves.
Very spectacular moves can be done in glowstringing, because the strings will give you lots of room to move and will allow some very complex movements. You can find lots of instructional videos on Youtube, especially for glowstringing, which is way more showy form of dance than freehand.
No strings are used as tools in freehanding, but all dance movements are made with holding glowsticks in hands all the time. It's not possible to make as complicate and spectacular moves as in glowstringing, but the video above shows that freehand glowsticking is showy enough. You can see freehand at clubs and raves, because it doesn't require as much room as glowstringing.