How have you used your skills to earn money in a non-conventional way?

This probably isn't the kind of answer you're looking for, but - for me - the answer would be volunteering services and mentoring.

It's not done with the motivation of earning money (otherwise it wouldn't be volunteering). But the network connections made and karma - if you will - that has come back resulting in job offers, people taking the time to teach me new things that ended up resulting in new opportunities, etc. have been numerous.

And while not money, I've made a lot of wealth of friendships in the same way who have helped me through tough times (some financial).