John Goodman discusses the growing online market for medical services in his 2/25/2012 TownHall.com piece, "Can Health Care Be Bought and Sold on eBay?".
Services such as MediBid allow patients to find elective services such as knee replacement at discounts of up to 50%. In effect, this marketplace allows patients to engage in a domestic equivalent of "medical tourism".
Unfortunately, Goodman notes that this sort of innovation is being threatened by ObamaCare regulations -- yet another reason to repeal ObamaCare.