There are no magical boxes, but there's a useful point on the knowledge spectrum to start with for just about every kind of tech there is out there. I'd never expect my mother to have to belt out something in assembly just to be able to edit the photos of the grandkids and mail them out to the family. But I would expect her to be able to understand that the computer is just another tool people will use to help them do work, and that will do what you tell it, no more and no less (assuming that it isn't broken.)
For my mom and most other people, I liken it to cooking (hey - I don't care who you are or what you're interests are, we all eat and most of us can't afford to have someone else cook for us our whole lives.) You don't have to know the laws of thermodynamics and chemistry and be able to calculate all the heat transfer properties and intermediate chemical reactions of the ingredients just to be able to bake a cake (or cookies if you think the cake is a lie.) Nor can you just shove the ingredients in the oven and expect to get a cake out of it. You should be able to know and identify what some basic ingredients are, and that there are some good and bad combinations to them, and a few recipes to start out with. It's too bad that this is a rather personal journey and that there is no general guidance other than to pose a few statements, maybe a problem or two that has some current relevance, and to have some resources on hand to point to for questions
The OP has the same work cut out for them that every other teacher in history has had. They want to share their wonder and inquisition of a specific, but broad topic to others and may not even realize that their audience might not give a damn. Not everyone who plays with wires gives a damn about power generation and electrical theory, some of them just want to get paid money to hook up the wires in someone's house to everyone else's wires.
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Their other problem is that they posed the question to slashdot, and are probably overwhelmed with the answers they got. It's like a thirsty stranger wandering in and asking for a drink at a beverage trade show - all they wanted was a cup of something wet to quench their thirst and what they got was a discussion on whether or not a particular seltzer was too much at first, or if milk counted as a drink, or some inflaming comments about those zealots who drink of the Kool-Aid.
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What I would like to see in the curriculum is a note that all of this software is only an example of a certain class of tool, and explain that there is a whole class of tool that each belongs to. They should give everyone the basic understanding of how some of the stuff works and a few examples that mean something to them. With every step of the way, remembering that you still need to reinforce the basics such as proper grammar and having your communications be a complete thought.
That way, you're not just teaching them to be end users, but helping them to be creators. Any fool can push the power button on a mixer if told the specifics of model such-and-such; most people can surpass that and go on to cook something that passes for a meal; only a select few ever go on to find their calling as a chef. I'd guess that this class should be the equivalent of being able to make most students a passable electronic cook. In the end they should be given the tools (which are free), and some examples with limitations of what can be done easily and what is unrealistic - how a spreadsheet can help you manage details in your budget, but can't magically manage the budget for you - how to pull the red eye out of a photo so you're not making a poster of someone look possessed, but not be able to fix the motion blur from a shaky camera - how a shell script can help you rename a bunch of pictures in a directory, but it can't sort them by content. Once given the basics, the ones with the interest will pursue it on their own.
Unfortunately there are lessons that can't be taught by citing a specific piece of software, reasonable backup/restoration (or any kind of security for that matter) is one. I wouldn't want to imagine the outcry from cutting off the power to a room full of computers while people are in the middle of their work. Yet I don't see how you can explain the importance of such practices without having some event with great impact like destroying their work.
One thing that I can think of adding (perhaps as an advanced topic) is basic networking, where wired networks are like passing a note to a friend whereas wireless is like shouting to them across a room. You can sometimes pass along what you need to tell them more quickly by sending them off a note than you can by shouting across a room. And when you start having everyone around you shouting it can get busy and overwhelming enough to the point where you notice that the things that are being said are now said more slowly because of all of the shouting. And everyone can overhear them (or potentially intercept the note) so don't shout stuff that's private unless you have a way of saying it that nobody else can understand.
Everyone crying for teaching them 'programming' has to recognize that everyone whoever creates a program has to be in the middle of two fields - computing (to be able to make a program in the first place), and whatever field the program is to be used for. I wouldn't expect to be able to take a CS graduate and have them just jump into modeling CFD simulations without having them first learn something about fluids.