Here's a quick and easy way to get to the flesh of a mango without getting too terribly sticky.
Hold the mango with the pit pointing north-south.
Take a sharp knife and run it down either side of the pit as close as you can go.
Take a large soup spoon and scoop out the flesh from each half of the mango like you would from an avocado. Dice and enjoy!
Caution: Watch how much pressure you apply because while the mango skin is thick you can easily punch through it with the spoon. Gentle but firm and Bob's your uncle!