I use different sizes of china-balls all the time. Build it yourself - and you have a wide range of uses for it. Put a ceramic halogen mount on a cable that can be put in your camera, og an external battery, attatch the ball and put it on a small pole (less than one meter) and attach it to your belts left side, support it under your left arm - and you have a soft light that will follow you. - do not use a light that is too strong. Less is moore. One extra tip is to put some spunn or frost - gel in the bottom hole of it so dou don't have to deal with the non-deffused light coming out of there. If you wish to travel light, you can allso use the china ball as an interview lighting - flag them out and you're there. It is allso usefull out in the bush (not for bigger shots, but OK for feature/documentary stuff) togeather with other battery gear such as dedo-lights. And remember: the bigger the ball is- the softer light becomes. And it is cheap. IKEA offer different sizes for allmost no money (At least here in Norway) Buy loads of them, as they are not constructed to last forever...
Good luck.
g