some good info out there.... just not enough yet....
start here
http://en.wikipedia.org/wiki/Aeroponics
but in a nutshell its like this;
roots need to be completely suspended, none should touch the floor
they receive a very short spray of oxegenated nute solution via spray nozzles capable of droplet sizes smaller than 80 micrometers (from a high or low pressure water pump)
spray duration is usually less than 5 seconds, roots hang in the air with no additional nutes for up to 10 minutes at a time, then short spray
this method uses 90% less nute solution compared to any other grow method
smaller water droplet sizes cause the roots go grow "hairs" making them much more bushy than hydro or other methods
not sure how or why, but this method is all about letting the root zone "air out", then when they get another spray of nutrients, they get like super absorbed by the plant.
according to NASA aeroponics has the highest production known to man (when done right!)