I use a meat cleaver to open coconuts (ironically, as I've never owned such a cleaver for use with meat). You can also use a knife, but we wrecked Andy's good knife doing this, and also they're lighter and thus more liable to "slippage," so I don't recommend it.
Some people whack it 3 times on top (this is the minimum), we started out with 5 and seem to have worked our way down to 4. Just make sure you angle in a bit, so the cleaver doesn't go straight through the side (soft white part) of the coconut. It may take you a few tries to get all the way to the coconut at first... just go over and over it until you get in!

• open the coconut top with cleaver (see photo)
• drain water into a wide-mouthed container
• split the coconut in 2 with cleaver (I hit it hard enough the first time to get it stuck, and then bang it 2 or 3 more times on the floor (usually on a paper bag) to get it through - Andy does it in one swipe... sigh.) (see photo)
• scrape out soft meat with regular spooning technique or harder meat with an upside-down spoon (the meat pushes away from the husk easier this way) (see photo)
• cut or pick hard husk pieces off of the meat before use

ENJOY!