I often work with binary data that has a format I could interpret if only I could see it in a human readable form. Most text editors aren’t much use. One way (of many) to solve that is to use the hexdump utility. hexdump is very versatile and allows you to look at the structure inside binary files as you see fit and once you learn how to use it you can apply it quickly to many problems. I think that easily qualifies as cool.