Steve Novella at the Neurologica blog just pointed out that this is the British Homeopathic Association's "Homeopathy Awareness Week".
He is right - I think we all need to be more aware of just how homeopathy can affect our lives. I encourage you to read Steve's post, which gives a quick history and an overview of what homeopathy entails. (See also the Science-Based Medicine blog.)
I also encourage you to look at what the carefully-assembled evidence from multiple scientific studies has to say about homeopathy. I recommend Ben Goldacre at Bad Science for this - here's a list of his Bad Science blog posts about homeopathy, and here's a particularly good overview. Also, anyone who can't imagine that their experiences with homeopathy could be "just placebo effects" should really listen to his two-part programme on the BBC about the placebo effect. You don't need to look to homeopathy for some mind-blowing, magical-seeming effects. There's plenty in the real world of scientific medical research. And read his book, Bad Science.
Bottom line: Real medicine is about proving something is safe and effective, and abandoning it as soon as it is shown to be either unsafe or ineffective.
Alternative medicine is about believing something is safe and effective, and rejecting, ignoring, or suppressing any evidence to the contrary.
It hurts people. It hurts people because alternative practitioners encourage distrust of real medicine in general. It hurts people because they take homeopathic treatments instead of real medicine. See for example this tragic story about Gloria Thomas Sam, a nine-month-old girl who died horribly because she was given homeopathic treatment rather than real medicine for eczema. Eczema!
Real medicine isn't infallible. But its researchers abide by strict rules of evidence: something must be proven both safe and effective before it is used in medical practice. Real medicine is self-correcting.
Homeopathy, and most alternative "medicine" modalities, are not self-correcting.
I encourage everyone - adherent, opponent, and uninterested layperson - to become a little more aware of homeopathy this week.
Bad Science cover art from Bad Science blog (assumed fair use).
Water memory poster from Hell's News Stand (adapted from a less politely-worded version; also available with a G rating). Published with invitation to redistribute.