It's not work, it's a hobby that (sometimes) pays. It's exactly the same as playing WoW, only more socially acceptable.
So when there isn't money in the bank you go out and you MAKE SOME DAMN MONEY.
If all else fails get an out-of-focus purely-for-money project. There's usually a lot of those lying about if you're willing to work on them.
full disclosure: my startup has yet to pay bills, but we have a knack for getting government grants
You should do what you love. Make peoples' lives easier. Financial gain is just a by-product.
Go out and change the world, with a passion to change the world (rather than financial gain), and the rewards (whatever they may be, money or otherwise) will come.