It's very easy to make a nice residual income (from $0 to $500 depending on effort!) by answering questions - Webanswers is a great site, easy to join, and with a bit of quality work (quality counts more than quantity) you can earn residual income.

I earn most money on Hubpages, but earn between $75 and $150 on webanswers by answering 10 questions or so a day (I built up a lot of answers to get to this though!)....