The one shill that I learned in high school that I still use to this day is keyboarding aka typing. I took keyboarding in my senior year and it was undoubtedly the easiest class I took, but it's also the only skill that I can directly point to that I learned in high school that I'm still using today, right now in fact.
I used to touch type and I thought I was relatively good at it, but I realized that it's essentially impossible to touch type faster than 40 words per minute, which is quite slow once you learn to actually type. I can type like 65 wpm, and clowns like Max can type like 85.
When I used to write papers in college and grad school, and even now in writing this blog post, I find it pretty helpful to be able to type at roughly the speed that I can formulate the sentence in my head. I'm not going to win any world records or anything, but typing quickly is a good skill to have.
All you kids out there (Keith Hernandez/Shaun Pertab) you should learn how to type.