Fiverr: Israeli-based Fivver was started in 2010 by Shal Wininger and Micha Kaufam. It's a great resource for selling just about any service online. You can offer gigs as low as $5 but also get paid much more for upgrades and add-ons. There are plenty of providers earning 6 figures on Fiverr so it's definitely a worthwhile cause for generating a healthy income. Just ensure that you provide some serious value.
Like writing (above) transcription is another type of work that often equals a full-time income. However, there are lots of sites that accept beginners that don't pay very much for the audio transcribed. While a professional transcriber may not bother with the sites below, someone without the skill to be a professional could use them here and there for some quick extra cash:
My name is Jamie Spencer and I have spent the past 5 years building money making blogs. After growing tired of the 9-5, commuting and never seeing my family I decided that I wanted to make some changes and launched my first blog. Since then I have launched lots of successful niche blogs and after selling my survivalist blog I decided to teach other people how to do the same.
Our first overlooked opportunity is selling your knowledge. In this instance, we are talking about creating a course or eBook that you can make available for purchasing online. Because of the automation available today, you may be able to put in the work once when creating your packaged information and then enjoy those checks coming in for months or years to come.