Rolf was kind enough to send me one of his triggers for testing.
I'm finding it indispensable for a lot of flash applications.
Simply place your flash on a little tripod and direct where you want some extra light for fill in.
I've tried over half a dozen different cameras from my Maxxum 7D to an old Olympus 2500L and the little controller is smart enough to ignore preflash from all of them.
The diode used is also sensitive to IR so I'm using to trigger with a little filter over the onboard flash at close distances without it showing up in the photo.
Just the other day I used it to flash my cars windshield from the outside while I shot super macro snowflakes from inside the car.
I think an on off switch is needed though because I'm already on a second battery.