If young coconuts came with a pop-top, they would probably be more popular than soda. At $1.50 a pop at Oriental markets, they are surprisingly inexpensive. While they look kind of like a cheesy novelty, inside of a young coconut is a juice that is very sweet and refreshing. After you drink the juice, you can open it up the rest of the way and eat the meat.
The biggest trick to having a young coconut is opening it and I normally whack it with a meat cleaver a couple times until I can fit a straw in.
This is one food where bigger is not necessarily better. You will find that the meat is softest and sweetest in the smaller coconuts.