How to talk to a doctor online for free (and for a fee)

It's Saturday night and you're coming down with something: itchy throat, watery eyes, pounding head, aching stomach. Do you push through the pain until Monday, when you can see your primary care physician? Or do you pick up your phone and, in a matter of a few taps, explain your symptoms to an online doc who can immediately advise you on the best course of treatment?