I have to completely disagree with Premed. I've taken several of my "core" studies online and quite honestly they've been more time-consuming than on-campus classes. Typically exams have to be proctored or the class is set up as assignments and discussions vs. exams in which you have to go really in-depth but can use your resources. I suppose you could make a case for whether it's really the student or someone else doing the work, but for proctored exams an ID is required, and for any other assignment the same could apply to an on-campus class. My only caveat would be to take online classes through a regular university vs. Phoenix U, or some of these other online universities. Every online course I've taken I've really enjoyed, and while it was more time-consuming I really learned a lot from each course. I can't say the same about all of my on-campus courses.
Good luck!
--Jessica, UCCS