Having discussed why it is important to have a second source of Income, let me now highlight some of the sources of a second income or second income ideas. A second source of Income typically means having regular income from a source other than your primary one. This means, if you belong to a salaried class, you might want an income from some other source and if you are from a business class, you might want an income from some other business. You can be as creative as it gets. Some good sources of Income are highlighted below:

2. Treat Passive Income like a game, cheating is using your spouses income in this game. I understand some of the premise behind this, but I’m married, my wife has an income and we have a rental house that we consider ours. I’m not sure how I would count this since we also use another part of our own home(also rental income) to pay down the Rental house.
It’s obvious, but every successful product solves a problem or fills a need- if the problem must be solved quickly, even better. What’s an urgent need? How about a car repair when you’re stuck on the side of the road (‘had the transmission on my car give out on a highway exit ramp. I don’t recommend it). Another good example is heat or air conditioning repair at home.
At age 55, I own high-end rental properties (near the beach) and commercial buildings servicing the medical industry. I was widely criticized during my career for not living up to my income; that is, buying big homes with many fancy cars. I married a great woman who understood that saving and investing today meant a better lifestyle and more freedom tomorrow. Our passive income is half of my active income from sales, but my net worth has increased substantially. We are both happier and healthier than we were in the high-stress pressure cooker of franchise sales. The naysayers have become converts to the concept of passive income, but they have locked themselves into a “big hat, no cattle” lifestyle. It has been a great ride!
According to 2011 census data, India has about 330 million houses and 247 million households. The household size in India has dropped in recent years, the 2011 census reporting 50% of households have four or fewer members, with an average 4.8 members per household including surviving grandparents.[331][332] These households produced a GDP of about $1.7 trillion.[333] Consumption patterns note: approximately 67% of households use firewood, crop residue or cow-dung cakes for cooking purposes; 53% do not have sanitation or drainage facilities on premises; 83% have water supply within their premises or 100 metres (330 ft) from their house in urban areas and 500 metres (1,600 ft) from the house in rural areas; 67% of the households have access to electricity; 63% of households have landline or mobile telephone service; 43% have a television; 26% have either a two- or four-wheel motor vehicle. Compared to 2001, these income and consumption trends represent moderate to significant improvements.[331] One report in 2010 claimed that high-income households outnumber low-income households.[334]
Multiple Streams of Income is chock full of advice. The investing advice is also great and certaintly better than what you will find say in JBQ's ridiculous book which cost many people millions in lost dollars. I saw a review here by Mr. Donoghue. My guess is that some people will try to bury that untill mindless 1 star reviews. If you can scroll back and read it, I highly recommend that you do. It shows a system of investing that yielded huge returns even during the Clinton "bear market."
I also noticed that in your passive income chart at the bottom that you don’t include your internet income other than sales from your book. Is there a reason for that? Do you not consider is passive because you are actively blogging all the time to create it? Or do you just not want readers to know how much money you generate from blogging activities?

What I find most interesting is the fact that I had never considered options like LendingTree or realityshares for other income sources. Investing in property has been too much of bad luck for people that I know personally, so I am interesting in getting involved in a situation where I would have to be dealing with maintenance issues or tenants. There are services for you to do that, but I had not come across any that didn’t eat most if not all of the earnings. Then again, I live in the NY area. Investing in the midwest would not be reasonably possible for me, directly, but reading about realityshares is something I am going to look into further. That might be a real possibility.
After employment, I think that most individuals gain income diversification through investing.  It is important to look at why we invest: because at some point we plan on using this money for something.  For most, it is saving for retirement, and the investing is done through vehicles, such as a 401(k) or IRA.  But investing is not just about stashing money away for a rainy day – that is what an emergency fund is for.  Investing is about having enough capital to generate income.
Chart 2 shows intuitively why the median of the symmetrical normal curve (half of the observations on one side of the median, the other half on the other side) overlaps the arithmetic mean (adding the value of the observations and dividing by the number of observations) and describes a representative situation, a common pattern illustrated by many measures of central tendency. This creates a business opportunity since we can define a large number of more-or-less similarly behaving customers.
I've got a $185,000 CD generating 3% interest coming due. Although the return is low, it's guaranteed. The CD gave me the confidence to invest more aggressively in risk over the years. My online interest income has come down since I aggressively deployed some capital at the beginning of the year and again during the February market correction. You'll see these figures in my quarterly investment-income update.
An obvious example is over exposure to bank stocks, which have been excellent investments for over a century.  Though a foundation of most portfolios, bank stocks do involve more risk at certain stages of the economic cycle than many realise.  Being less exposed to bank shares in the last few months could have preserved some capital.  So, a more diversified approach can help mitigate some of these risks.