I've always been pretty involved in the automotive industry (hobby of mine), so got to write a bunch of neat web apps to do with it. Inventory/parts interchange stuff that connected a bunch of different online retailers together so they'd save time calling between each other to see who had what in stock, and kept track of pricing models to use. The total scope of the projects is really off-topic for the thread :). Got a lot of the people interested in that through a big trade show a few years ago when I was going through a lull in freelancing jobs.

Honestly, money is the least of my concerns. I don't have any interest in working for free, but I'm billing out around $100 to do CMS work. All of which is mindless for me. I'd rather take half as much and do something I enjoy.