CONTAINS SPOILERS

Early on you'll notice glowing orange lights that are usually situated in hard to reach places. You can't use these until after a certain event in the game. These are grapple points. To obtain the Icarian Grapnel which gives you the ability to use these, defeat Ixion, the boss of the second area (Crimson Wastes). After that, simply look at the orange lights and press Triangle to grapple.