I'm starting to use MedHelper for Android as a tool to keep track of my medicine. As you get older, it's more and more likely that you'll be on some medication, and since I've had side effects from previous meds I'm happy to find something that helps me track things.
It's a relatively complicated program compared to some simple pill reminder apps on the market, but my use is relatively simple. There's a reminder function to alert you when it's time to take your medicine, a log that tracks when you actually did take your meds, and a simple comment log that lets you add notes about how it's going or any side effects you noticed. If you're doing detailed logging of weight, blood pressure, or a number of other vital signs there's a place for that.
At the moment there's no web-based version of it, but the site hints at a "cloud" version, which I suppose I'd welcome.
The test of any software like this is twofold. First, does it help you actually follow your prescription better than a simple alarm or a pillbox. Second, does it help you when you are at the doctor's office talking about your health. I haven't tested either, but I'm looking forward to updating this review when I get a few months of actual use in place.