And then there's always waiting tables. A bit of a shot to the ego perhaps, but that'd be a good break from coding perhaps. If it's good enough for every budding actor/screenwriter/director in LA... :)
Still you have to be very careful it does not take your focus away at any point. My partner had freelanced before so he knew what kind of projects to take and not take. Best projects are those that pay for some straightforward coding without much mental work.
So while I'm sure you can find some job to pay the bills, consider how much time (and in what state mentally/physically) it will leave you to focus on your startup.