Scutwork involves doing menial (and often meaningless) tasks that are necessary for patient care but do not contribute to your education. For example, filling out forms, running to get an x-ray, waiting by the phone for someone to answer a page all fall into the category of scutwork. Scut is the job of the housestaff (especially the interns), not the medical students. The only exception is if you've never done the task before...
A certain amount of scut must be done in order to keep the team running smoothly. Most residents are keenly aware of it and won't scut out the med students unless the service is swamped. Doing scut is often a good way to pitch in and help the team -- it doesn't require an MD to do these things, and your colleagues will appreciate your help.
Cheers,
doepug (MS IV)