good luck with those exams bro... i wish i would have tried harder in school... believe me, its worth missing a couple workouts, and i doubt you will lose any noticable strength...
i just started working my neck the other week... re-read that thread that SL posted about a year ago on 'training the yoke'... so once or twice a week i'll be doing some neck curls on the ham curl machine, sitting the opposite direction, face down... will keep the weight fairly moderate for 15-20 reps...
i swear i can already see a difference...