when inline css is useful

http://developer.yahoo.com/yui/examples/container/overlay.html

The markup for overlay1, plus the context element ctx and the buttons to show all our Overlays, is displayed below. Note that overlay1 has an inline style of visibility:hidden set in advance. Most browsers are slower to render CSS than inline styles, and we want this marked-up Overlay to be hidden by default. If the inline style isn't present, it may cause a brief "flash of unstyled content" where the Overlay may be visible on slower machines.