Whenever I can fit a few minutes in, I'm down for it. With school and all the crap that comes with it (papers to write and novels to read), I'm happy if I get an hour a day in to study. I know it's not much, but when you're swamped, you do what you can. Basically, my advice to you is, from now until the MCAT, study for that damn test! Don't worry about other people and how they study so much, but rather try to maximize the amount of time you have to study and work as many sample problems as you can. That's all I can offer for now. Speaking of the devil, I should probably stop writing and go learn something in my MCAT book.
Take it easy
Atlas