The O'Clock exists as a tangible entity too - that is: I've made one prototype so far. Here are photographs, showing the time at 10:31 and 10:58.
And of course, there's the screensaver. For MacOSX, NextStep BackSpace and Macintosh After Dark (both still referring to it under the old name of Tiggr's Clock). O'Clock screensaver for Windows '95/'98/NT. Tiggr's O'Clock as a module for xlock: diffs for xlock 4.13.