Hi,
This is a late reply to the question from the previous poster

but I am relatively new to the forum. I got wireless HSS to work using two Pentax 360 flashes. It worked using the following procedure. There may be others that work as well. One flash needs to be on the camera. This flash is set to PTTL, the flash set to HSS, set to wireless mode and set to 'c' command mode. The second off camera flash can be placed where you wish within reason from the on camera flash. The second flash is set to PTTL, the flash set to HSS, set to wireless mode and set to "s" slave.
Needing two flashes sucks, no doubt about it. But if you already have two, the loss is not so great. The key fact is that the range of the flash in HSS mode is very short. Therefore if your subject is just a short distance from the camera, the flash on the camera is not going to contribute to the exposure anyway. Also, the second flash that is off camera needs to be placed very close to the subject to provide any light. So why would you bother?
This could be useful if you want to take a portrait photo in daylight and the background is especially crap. You can use larger apertures such as f/2.8 and shutter speeds that exceed 1/180 to darken the scene. For example with shutter speeds of 1/2000 (need to adjust according to your scene) most of the picture should be dark (depends upon the sun light), the background out of focus, while still some flash illumination on your subject.
A bit of a hassle, but still kind of kewl.