Willing to share?
In general outline, sure.
Several of them are essentially arbitrage schemes for investments. In much the same way that a hedge fund leverages loans to build a risk profile, a person with enough capital can find low interest money and apply it to higher interest areas. Credit card arbitrage is one form, or a HELOC, but places like Lending Club allow you to both borrow money and lend money. A competent investor could utilize that spread for passive income if he knew enough about distributed risk profiles.
Several of them are teaching skills that I already have. If you are an expert at something, chances are good that you can either charge people directly to pass on that knowledge or work as an independent contractor for someone else's business. Examples might be music lessons, teaching martial arts, SAT prep classes, SCUBA instruction.
Many people with professional skills who currently work for someone else can likely replace at least part of their income doing the same job as an independent. Consider that your work is theoretically profitable enough that somebody else is paying you to do it and making money off the top from your labor. Stop giving away your earnings and work for yourself. In many cases, an employer offers that air of credibility, economy of scale, or list of contacts that an independent might not have, but if you are good enough at your job you can build all of those things around yourself personally instead of around your employer.
Small scale manufacturing or assembly, in your own home, can pay a decent hourly wage if you're creating a product that is horribly enough overpriced. These are usually specialty items for expensive hobbies, but things like desktop computers also usually retail for about 60% markup over the cost of their components, and can be assembled in less than hour if you know what you're doing. Keep in mind that Spanx lady starting making underwear on her personal sewing machine and is now a billionaire.
Write a book or a piece of software. Either going through an agent or self-publishing, even a moderately successful publication generates passive returns once it is set loose on the world. It's a lot of work up front, but for someone who enjoys the creative process it can be a way to make money off of something you were going to do in retirement anyway.
Pretty much any of these jobs can be outsourced, if you don't mind contributing to the downfall of the American economy. If there is money to be made by doing a job in the US, there is probably money to be made by paying someone else to do that same job, especially if you can pay someone in India. Even keeping the labor local, there is basically no limit to how many businesses you can start up if you're just paying someone else to do the work you would otherwise be doing yourself.
And that's the real secret of capitalism, I think. The vast majority of the workforce is working for someone else's benefit for a fixed wage, instead of taking profit from someone who performs labor for you at a fixed wage. The more little businesses you run, the more diversified your income stream becomes, and the less risk this entails.
