TAMRAC release MicroSync,
the Worlds smallest and lightest wireless radio slave flash trigger.

Microsync Digital is a tiny, advanced radio transmitter which slips onto the hot shoe of your camera and wirelessly transmits a signal to the receiver unit in order to trigger your flash when the camera shutter is fired.
Measuring just 27x51x11mm and weighing just 30g, the transmitter is significantly smaller than other systems on the market and just a fraction of the weight. With 4 channels to choose from you can also maintain separation between yourself and other Photographers running Microsync nearby.
Both the sender and receiver incorporate an advanced automatic power management system which turns the units on when the shutter is pressed and off again milliseconds later, giving an expected battery life for the receiver of 3 years. Since this power management is totally automatic with no on/off buttons there is no chance of accidentally draining you batteries by leaving the unit turned on.
Adapters are also available to link Microsynch to your cameras PC socket if the hot shoe is occupied, or to link it to your PC socket equipped flashmeter for wireless test shots.  Additional senders & receivers are also available separately.