I was doing a little digging on the web and I've noticed a discrepancy between the threshold given for tasting salt. Most of what I've read here and on the SWG manufacturer's sites list 4000 to 6000 ppm as being the point at which most people can taste salt. Earlier this year I added enough softener salt to my pool to bring the level up to 3200 ppm (as measured by the Aquacheck strips). The first time I used it after adding the salt I immediately noticed the salt taste. Everyone else who has used the pool has also commented on being able to taste the salt. I was kind of surprised since I assumed I was below the threshold of taste. As of today, the salt level has dropped down to 2400 ppm (due to backwash, splash out, etc.). Even at this level the salt taste is very obvious.
I recently came across this Australian site: http://www.sa.waterwatch.org.au/sw_salinity.htm. What was really interesting was that it clams water "would start to taste very salty" somewhere between 480 and 1500 ppm. This is significantly below the thresholds I've seen stated other places, but would seem to better correlate with what I'm seeing in my own pool.
The other part that was interesting was the comment that "Some plants such as peas, apricots and grapes cannot be grown with water over 1500uS/cm". Based on the ranges shown, I'm interpolating this is approximately 1000 ppm. This could be significant if you live in an area where your backwash water is not being pumped into the sewer system. Yes, I know some people have backwashed their water for years near plants, trees, etc. with no issues. I'm not saying its a problem, I just found it interesting.