I came upon this link of podcasts re: American
History.
Podcasts of Previous Teacher Seminars
I haven't watched any yet, so no idea of the quality, but it seems that people cruising with
kids should actively seek out sites like these and download them prior to setting sail. You could cram quite a few semesters worth of lectures into a
laptop.
Also, for we geeks, these could be nice for long passages, even without sharing them with the
kids....