Initial high-frequency data for September, though, point at a recovery in EM central bank demand for the common currency.

FORBES: EM Central Banks To Gobble Up Euros After Sharp Drop Against The Dollar

These were the direct ancestors of the "co-location" and "direct data feeds" that have enabled high-frequency traders to get first crack at market prices on today's stock exchanges.

WSJ: New Twist Is Added to an Age-Old Saga

One such project is called NewsFlash, and uses high-frequency red and green light to transmit data to the built-in camera on a receiving device -- in this case Samsung's Epic 4G.

ENGADGET: NewsFlash uses high-frequency light to transmit data from iPad to smartphone, we go hands-on (video)

Not all planes across oceans have data-link capabilities, and high-frequency radio is still used with some flights and as a backup with others.

WSJ: How New Air-Traffic Control Systems Operate Over Oceans