Salt is great for enhancing flavour, but it plays a bigger role in the chemistry of cooking than you might think. The folks at America's Test Kitchen point out that if you're boiling green veggies, a few pinches of salt in the water can keep them bright and green while cooking.
For the best effect, pair a little salt (to keep the chlorophyll from leaching into the water) with an ice bath after removing the vegetables from the water to help stop the cooking process. ATK also explains in the video above how to use a pinch of salt to keep coffee from being overly bitter (a trick you may have learned from Alton Brown), and why adding a little salt to your scrambled eggs will keep them smooth and creamy instead of firm and rubbery.
3 great Uses For Salt Besides Making Stuff Salty [America's Test Kitchen]