well thats a bit different my idea what i meant was like the led glow ball poi but much smaller like the size of the wooden handles
I kinda realised that but was distracted. Most ready made led balls are pretty big, to allow for batteries, circuit, shock absorbtion and light diffusion.
There are a heap of really small lights, some fairly sophisicated, that the glove light show ravers use (photon etc), I've never looked closely at them but if you could enclose one in a clearish casing I think it'd work OK for size and light but I don't know if it'd weigh enough to make a good counterbalance.
Obviously it'd depend on how much your poi weigh.