While it's a slightly unpleasant activity, you could sell your blood plasma.
I did so for a few years.
You can go twice a week, and they typically give you approximately $30 each time.
To make it as quick and comfortable as possible, have a greasy breakfast beforehand (thins the blood, so the process goes more quickly) take a jacket (because the fluid they put back in you is room temperature, and feels really cold. Take a DS or PSP with you for entertainment, because they do show movies at most of the clinics these days, but you only get to see a portion of them. If you have something soft to squeeze, like a foam ball, or a rolled up glove, you can speed up the process.
And as an extra bonus, you get the satisfaction of helping your fellow man.
This page has many numbers of blood banks and plasmolysis clinics in California
You can call around and see whether they offer payment for plasma, and find out specifics.
Hope this is helpful to you.
EDIT: Fixed my misspelling. I was hurriedly typing so you wouldn't take silent sniper's suggestion first.
(You can't make money selling pot. )