Place the graham cracker crumbs in a food processor. Grind until crackers become a fine crumb. Transfer to a medium-size mixing bowl.
Add the sugar and salt, and mix with a spoon until well combined.
Pour in the melted butter. Stir until all the crumbs are evenly moistened.
Pour the crumbs into a 9-inch pie plate and spread into an even layer. (If your plate is smaller, you'll have a thicker crust.) Using your hands, or a flat-bottomed measuring cup, press down on the graham cracker crumbs. Start in the center of the pie plate and work your way out and up the sides. You need a stable bottom for the pie first.
Bake for 8 minutes. Remove from the oven and let cool off at least 10 minutes for pies that need to be baked. Cool completely before filling for cold pies.
If you don't have a food processor available, place the graham crackers in a gallon ziploc bags and beat the crap out of them until you get a fine crumb. Continue as directed.