Drag a picture onto blurfaces.org, hit Blur, and it will obscure all the faces it finds. You can toggle individual masks or tweak how strong the blur is. For now it works with still photos only, but it’s been surprisingly handy for family shots and marketplace listings.
I’d love to know: does this scratch an itch for you? What’s missing or annoying? Would you use a tool like this, or do you already have an easier workflow?