let the sparks fly?

A poser to all you teckies out there. Does anybody have an answer to how we can create sparks to occur during a sword fighting sequence? During a sword fight rehersal for our performance for Peter Pan we did have a couple of sparks fly, the effect was "electric" and we would like to reproduce this on cue each show. There must be some elements that could be coated to one sword that would create sparks when struck by another.

Jaguar