My esteemed marketing colleagues initially balked at the idea of creating products that generate royalties, so I can understand how creating something from nothing might be daunting for those who aren’t even in creative roles. However, realize there is this enormous world out there of photographers, bloggers, artists, and podcasters who are making a passive income thanks to the Internet.
That strategy seems waaaayyyy less risky than actively picking stocks of supposedly “reliable” stocks that issue dividends, which could be cut at any time due to shifting industry trends and company performance. Dividend investing feels like an overly complex old-school way of investing that doesn’t have a very strong intellectual basis compared to index investing.

P2P lending started in San Francisco with Lending Club in mid-2000. The idea of peer-to-peer lending is to disintermediate banks and help denied borrowers get loans at potentially lower rates compared to the rates of larger financial institutions. What was once a very nascent industry has now grown into a multi-billion dollar business with full regulation.
I’ve read stories about people setting up ad campaigns and making thousands of dollars within a matter of hours. What’s the catch?  The big one is risk.  You’re spending money to make money, so if you turn out to set up a bad ad campaign that doesn’t convert well, you can easily lose lots of money.  That’s been the primary reason I’ve stayed away from this method of making money online.  I’m not going to bother giving advice here, because as I said, this isn’t something I’ve done.  If you’re interested, you can probably find a lot of good information via Google, but watch out – as with any other internet marketing topic, most everyone is going to try to sell you something.

It’s obvious that stocks outperform real estate in terms of capital gains, but I would like to see S&P compare to Real Estate in SF, Manhattan, LA. Our house in NC was $80,000 20 years ago. It’s only $150,000 now. Same house in Santa Monica went from $200,000 to $1.8 million. People who happen to bought real estate in major metropolitan would have a natural positive association with real estate investment.

Although adding income streams takes time, creating them within your current business is faster and easier than starting completely new income streams from scratch. This method of generating extra sources of income works well for any size business in any industry. For example, started by selling books. Today it sells thousands of other products including its own product, the Kindle, is a print and digital publisher, and now produces television shows. Many service-based business owners add coaching and books to their income streams.

Wow! What an awesome list! My favorite is the stock photography because I love photography. I have had some success there, particularly with one photo I make some decent income from. I think the key with stock photography is finding a shot that is high demand. Then, find a new unique way to frame that shot. This is the reason my St. Louis Arch photo is a top 10 on both ShutterStock and iStockPhoto. Thanks for the awesome ideas above!
Real-estate crowdfunding ($9,600 a year): Once I sold my SF rental, it was natural to reinvest some of the proceeds into real-estate crowdfunding to keep sector exposure. I didn't invest a lot in some of my favorite real-estate investment trusts because I felt a rising interest-rate environment would be a stronger headwind for REITs. But if I could be more surgical with my real-estate investments by identifying specific investments in stronger employment-growth markets, I thought I could do better.
Question: You mention receiving $200k of passive income a year, but your chart shows half of that coming from real estate holdings, and reading between the lines it appears that you hold mortgages against those holdings. Then you conclude that $200k/yr of passive income should be enough to live comfortably anywhere in the world. So are you subtracting your real estate expenses (taxes, insurance, mortgage payments, maintenance, remote property management company fees, etc.) when you report your passive income from those properties? Really I think it’s the net (after taxes and everything) that tells us what is left over to “spend” on living, right? When I set up my spreadsheet to retire early at age 47, I calculated the after-tax income I would need to live. Then I compared that to my income streams (estimating tax on the taxable income streams) to measure the surplus/shortfall. Also some good advice from GoCurryCracker: If you can minimize your taxes so you’re in the 15% tax bracket, you can possibly receive tax-free long term capital gains. I agree with your philosophy that time is more important than money as we age. I am not sure I agree with a philosophy that is fixated on needing such a large income, and would rather minimize taxes if it’s all the same on the happiness meter. Furthermore, having 20 plus income sources in the name of diversification adds stress and requires more management (TIME!). I think this is fine for those of us while young, as we have the energy to work hard. But as time becomes more important, the extra headache of managing, planning, and buying/selling our assets becomes a resented hindrance on par with the resentment we felt when working for an employer and fighting traffic each day to go to a job we hated. Every thing we own in actuality owns us, by virtue of its demands on our time and affections, and that includes investments. It also includes our home, and is a good reason for downsizing. As long as we have food on our table, a roof over our heads, and clothes on our bodies, what more do we need? I think we need to consider freeing ourselves from the weight of the chains of managing too many ventures. Personally, I plan on investing in no more than 5 simultaneous ventures ever, with the exception of some IRAs that I just plan to let sit for the next 20 years (and therefore no thought or anxiety required).
What I’m doing: My realistic goal is to have a blended annual return of 2x the risk free rate. With a current 5% hurdle, I am not paying down mortgages that cost less than 4%. Debt at 5% is a wash. My realistic blue sky scenario is a 3-4X rate of return over the risk free rate which can be achieved with property, stocks so far for the past five years, and certain private equity investments. Where I am dragging is my blended average CD interest rate of roughly 3% from an old CD coming due. I’ve rolled some money into a 12-month CD with CIT Bank at 2.5%. It’s the best rate I can find. 

Don't mistake passive income with zero work. It's still work, it's just that your income is not directly tied to the hours worked. Anyone who owns rental properties knows that it's considered passive income but there is quite a bit of work involved. The work is front heavy but if you are lucky, you can collect rental checks without incident for many months before having to do work.
To your point about Municipal Bonds, my concern is tax reform. While everything is mostly being worked behind closed doors (and likely wont ever see the light of day). There is still the chance they propose to limit the amount of the tax free nature of these bonds. While I dont sen panic in the streets, I do see a scenario where bond prices get additional pressure because municipalities have to increase rates due to people putting their money to work elsewhere.
Stocks (shares) paying dividends are typically a reliable source of income but they have higher risk of capital losses than cash and bonds. So, it’s wise not to chase yield indiscriminately.  The 10 highest yielding stocks on the ASX 200 (the 200 largest companies in Australia) are shown in the table below.  But their share price performance on average over the last year has been underwhelming, as shown in the far right column: