At my high school, I rarely, rarely see kids get in trouble for swearing. Unless you say it directly to a teacher, the teacher will not make note of it. Kids swear all the time when the talk, or talk about drinking or stories from the weekend, and 9 times out of 10 the teacher will not say a word. The worst I remember is my gym teacher said "Hey, watch your language" to a kid who literally screamed "Fuck" at the top of his lungs, outside during a flag-football game. The kid then brushed the teacher off, and nothing else came out of it. Kids even say cuss words directly to teachers (not as insults), but with quite a few teachers, if you say "damn" or "piss" or "hell" they take it in as normal conversation. This is only a few teachers, and then again at my school we have a lot of young teachers. My High School is also a pretty well-to-do school, so its not like its a place where all sorts of bad things happen all the time.
About cell phones, kids take them out in class all of the time and send text messages. Some kids even make calls during class (discreetly, or maybe at the end of the class), and teachers don't do anything. They pretty much have the "it's your responsibility to learn the information" attitude, and let it go.
Hell, the other day I mistakenly thought that school was over (we are on block schedule, and class orders are switched around on different days), and after class I literally walked almost the whole length of the school talking with someone on a cell phone. It took till I was almost out the door (again, I was about to leave because I got messed up on what day it was), until a teacher made note of it. She just told me to put it away, and I immediately felt like an idiot because I almost left school with one class to go.
*EDIT - My school also allows students to carry backpacks around school. Also, with iPods, while we are not supposed to use them in school, I have a few classes where I can take mine out and listen to it while I do my work, and im sure there are a lot more. Kids even walk around the hallways listening to their iPods.