In Google Health you can now add your health information. You can add your diseases and medication use. The systems alarms when dangerous interactions appear with your different medications. You can also add allergies.
You can even add medical records from sources of which a few of are shown in the next figure
When you link a website to your profile, you may authorize that website to read your Google Health profile or to automatically send and update information in your profile (such as medical records or prescription histories). You decide which permissions to grant when you sign up with each website.
All you need is a google account.
If you're willing to hand over your medical profile to the big G in the name of convenient info, Google Health is for you. The more privacy-minded, of course, may refrain.