The Digital Diagnosis

In an age in which mail-order pharmaceutical spam clogs our e-mail inboxes, how can we trust the health information we find online? If you have a serious health problem, you should see a physician, but if you want to do some independent research, can these sites really give you accurate information? I used my sore neck as a good excuse for surfing to some of these sites to see whether their diagnoses jibed with a live doctor's assessment.