Boiling water

You know how some people add salt or other things to water to help it cook faster when they are making a meal? Well, is there a valid reason for that, scientifically?

What is the fastest and most economical (uses the least energy) way to boil a pot of water?

Cheers, eh.

You should go to a very high elevation, and it will boil at a lower temperature, so I assume will require less energy.  But, the energy costs of travel to a place like La Paz may cancel out your cost savings in boiling the water.

You also want pure distilled water.  Dissolved substances will raise the boiling temperature and thus require you to heat it longer to boil.  If boiling water is your goal, this makes it boil slower, not faster, but on the other hand if you need hotter water in which to cook something  then the salt does help increase the temperature of the liquid. (At high elevations, the lower boiling temperature makes it more difficult to cook something without using a pressure cooker.)  The amount of salt typically used, however, may not have a noticeable effect.  This topic is authoritatively discussed by a bunch of PhD types at a U.S. Department of Energy webpage.