uh, 4th year. i know not all schools allow people to arrange their schedules this way, or give the option of having that much free time, but many many others have substantial free time in 4th year. it's the perfect time to do that kind of thing.
as an aside, i would recommend, if one has the option, to look into what the 3rd and 4th year scheduling set-up is at the school to which you are applying or thinking of going. it makes a difference if a place is willing to be more hands-off, and let's you do what you want once you fulfill the basic requirements. for me it makes a world of difference. i met a few folks on the interview trail that had sub-i's and all sorts of required rotations throughout the spring of their 4th year. it's one thing if you elect to do it, but oooooosh, i would hate to be forced to do that right about now.
