Getting paid to take surveys isn't new, but the availability of the internet means that you can now get paid to take surveys on just about anything, by anyone around the world. It's not really a passive income source, but it could boost your income whilst your waiting for your passive revenues to grow.
As a child I was involved in a couple of focus groups for Smash instant mash potatoes, so I knew this kind of thing went on, it's just never occured to me to be a particularly interesting way to make money. And surely you'd never get paid enough to really make it a viable income stream. And then I came across www.paidsurvey.com.au who promise earnings of up to $150 per hour, with cash paid out daily. Rather than provide the surveys directly, these guys provide a directory of websites and other businesses that will pay you to take surveys.
If you'd rather go straight to the source, Valued Opinions actually pays for you to take surveys from leading Australian brands. You will typically be paid between $2 and $5 per survey, and up to $50 for specialist surveys. More information here.