I guess I've come around a bit lately, but only because I recognize (as Wordead stated) that away rotations are the practical thing to do. Away rotations are one way for a department to get to know you. I still maintain my position, after having seen many medical students do away rotations, that away rotations tend to hurt students more than help.
Generally speaking, students aren't helpful any more in the way they used to be helpful in the era of paper charts. That's not the student's fault, but one of the tests of a good sub-I was the ability to pre-round, collect the data and write the notes. I remember when I was a resident, a good sub-I had progress notes in his or her pocket already filled out with everything except the plan, and the note was just inserted into the chart after we as a team came up with the plan. Can't do that so much any more. With COWS and automatically generated sign out sheets with labs (hey, they even have that CBC and Chem-7 skeleton drawing thingy!), residents can generate the data on the fly. Most notes are cut and pasted these days. There's no work involved. Some institutions have PAs and NPs on the floor -- floor work is now something of the past for many residents and students. So, what's left? Students come to clinic or the OR, generally unprepared. This may not the student's fault if the team tells the student what he or she will be doing 5 minutes before having to be there. But, a lot of students end up on services, which many programs have. If you're on the head and neck service for a week, you better be reading about anatomy, cancer, staging, etc. You need to take a look at the OR schedule the night before. Maybe stay late and read the charts or go through the scans instead of just showing up and expecting be be taught. The latter is what most students do. When students are in my clinic and don't know the basics of an audiogram or when they come to the OR and don't know why I'm doing a mastoidectomy or don't know simple anatomy questions, I really don't feel like investing any time in them.
An away rotation is an interview and a test of your work ethic and fund of knowledge. You need to get this right, and that requires that you be the first in and the last out and being well-read. When you leave in the evening, whatever time is left in the day should be spent preparing for the next day.
I've been impressed by a lot of students -- some more so than my own residents. These rare gems are "on the ball" and just know everything about the patient(s), are helpful in clinic, know how to present, are prepared for cases and ask pertinent questions that suggest they've been reading. These students have a history of strong work ethic and team building/playing.
Just work hard. Be present. Know your patients. Know your role, and don't complain about having to do **** work. We've all done it...and still do it.
And stay off your cell phones. In fact, don't bring them at all.