“Continuous” refers to actions which are uninterrupted: “My upstairs neighbor played his stereo continuously from 6:00 PM to 3:30 AM.” Continual actions, however, need not be uninterrupted, only repeated: “My father continually urges me to get a job.”

Brians, P. (n.d.). Common Errors in English Usage. Retrieved November 19, 2012, from http://public.wsu.edu/~brians/errors/continual.html