There are many ways to trigger a synthesizer, but if you're a tactile sort, Rory Harnden's could well turn out to be your favourite. In his Body Music video, he demonstrates that it's possible for people to make electronic music simply by touching each other.
The synth involved was made for an ergonomics class and works when wearers of its wrist bands touch each others' skin. We don't have the full technical specs, but the video seems to suggest that different types of touching generates different types of sound.
You can watch the Body Music clip here. It's all very sensual and everything, though we're not sure how practical this method of music making would be in a live performance situation. And to be honest, the thought of The Chemical Brothers doing this to each other turns our stomachs.