Back to "ways to make money during med school"...
I have thought about this quite a bit. "They" say that ever dollar borrowed from a Grad Plus loan is like borrowing three or four once it's paid off. So even if you earn a little side money, it can reasonably be considered worth three times its value because it is less money borrowed.
I'm aware that many schools have students sign a contract stating that they will not work during school. However, odd jobs should be OK, ideally if they take up very little time, require little to no travel, and are paid under the table.
Someone mentioned pet sitting. This is a great idea, and I've done this throughout undergrad. Another idea is tutoring high school students. College students have access to free services at school, but AP students have parents who are looking to save money on college tuition. They will pay you a small fraction of their savings to help their child be successful. The going rate for private tutors is $40/hour. (Give a discount if it's more than 1 hour per week). Also, this requires very little brain power, because it's stuff we are aces at (intro chemistry, physics, bio, etc.). I've found it to be mutually beneficial and actually quite fun. Then again, I love to teach.
I am also wondering about freelance writing for websites and blogs. Has anyone done this, and if so, any tips or recommendations?