It's a nice ingredient to have on hand. It's a good emulsifier, and some sprinkle it on food for a nutritional boost. Myself, I use it in baking. especially for the whole grain sandwich bread I make every week, it really improves the end result. The bread slices nice and thin and stays pliable (no disintegrating sandwiches). It's important to add it to the liquid ingredients, not the dry ones so it mixes in properly. A little goes a long way. I use 2 tsp per 2 lb loaf.
It should be stored in the refrigerator or freezer, with the high oil content it can go rancid if stored at room temperature.
You can get granular lecithin from King Arthur Flour and Bob's Red Mill.