Hi folks, I have just realised that I made a mistake in an earlier post, reporting that the Olympus E-1 and E-3 can do the high-speed sync trick. I felt there is something wrong, as the E-1 has a full-frame transfer CCD, which excludes implementing an electronic shutter by construction.
So why could I do it? Well, I have not admitted (even to myself) that I could do it only at full power! I think you have already guessed it - the full power flash duration with the SB-28 is long enough to cover the time while the "slit" the shutter creates travels through the frame (independently of the actual shutter speed). This way, you can sync at any speed without having an electronic shutter in your camera. Limitation: you must use full power on the flash (accepting relatively slow recycle), and this gets reduced beyond your control as shutter speed gets faster. Benefit: if you find the right combination of flash and camera, this will work on a dslr without electronic shutter.