It had to happen, a cheaper version of the Pocket Wizard wireless TTL flash triggers is coming onto the market by Christmas 2009.
The new Pixel Enterprises TR-331 (for Nikon) and TR-332 (for Canon) consist of a transmitter only (TX) component and a receiver only (RX) component which use CR-2 lithium batteries but no transceiver to allow use of the speedlight on the camera itself (which is a real pity – I hope they will make a transceiver version).
They differ from the Pocket Wizard Flex TT5 in that they use the 2.4GHz radio frequency and thus do not need different models for each region of the world (but perhaps there may be interference with other 2.4GHz devices such as portable phones), and although they support High Speed Sync (HSS) flash to 1/8000th sec, they do not appear to have Pocket Wizard’s Hypersync mode, and they do not appear to require use of a laptop and USB connection to program them (but I presume they are much less sophisticated devices and thus less versatile).
They have 15 channels, and are said to operate up to 65 metres, support auto-focus assist, and also have a PC sync socket to fire studio strobes or manual flashes
Now if only they would bring out a much needed Olympus model.
More information on their website.
UPDATE March 2010:
Jack from Pixel Enterprise informs me that he can supply these Pixel TR-332 radio triggers directly and currently will cost a very reasonable $US180 for the set of transmitter and receiver for a Canon e-TTL with postage charge of $Us25 by Express mail to USA or Australia (can pay via PayPal) . If you prefer you can search for them on Ebay, or if you are a distributor, you can purchase them in bulk at a reduced price.