Find a way to make some money as a graduate student that either complements or doesn't interfere too much with my studies

I’ve got an idea for an iPhone app, which uses some of my grad-school experience and even relates a tiny bit to my research. I’ve got about six weeks left until the Fall semester, so I even have some time. Here goes.

How could this be done?

The main problem of a grad student is focus. The academic world exerts strong pressure to fragment your attention: taking three classes and helping teach one class, you switch tasks so frequently that you never get even one full day on anything, much less the week-by-week continuity that you need to accomplish anything real. Adding a job into this mix adds even further to the fragmentation—a recipe for misery and failure.

Could earning money be done in a way that increases focus rather than causing distraction? So far, I have two ideas for how it could be done:

1. One quarter, take just one class and work a short-term job, like a contract job. You won’t get a tuition waiver that quarter, but your tuition should be low since you’re only taking one class. Ideally, the class is an independent study, so you’re now spending 50% of your time on something meaningful. That still sucks, but it’s a big improvement. This move delays your graduation some, but hopefully the more-focused semester means you graduate with something accomplished. The delay is much more severe in a school on semesters.

2. Work as a security guard. Unarmed security guards basically sit around doing very little except having truckers sign forms when they come and go. You get lots of time for schoolwork.

Any other ideas?