Hello,
After having a conversation with one of my colleague (Ian), I couldn't resist, and I happened to have some spare time while helping a TA as an unofficial TA. So I made a Clock project in Etoys.
The file is available at:
http://dev.laptop.org/~yoshiki/etoys/Clock.004.pr
One way or another, please load it onto Etoys (on a non-XO environment, drag-and-drop from Finder or Explorer. On XO, access the URL with browse, copy it to a USB memory and resume it from Journal, or hit Alt-, for "Show Source" -> 'open...' -> 'file list...' and navigate to the .pr file).
After it starts, don't forget to move the mouse around!
The fun thing about it is that only non-trivial thing the user needs is a text version of Clock that is available in the Object Catalog. Everything else is built with simple Text, Ellipse, Rectangle, and Star. (The digital clock uses another pre-made widget.)
The essense of rotating the analog clock hands is three equations each of which decides the angle of a hand. The script shown in the project has such three lines. In the other words, kids don't have to know any more magic than setting the heading of objects. (The script has other two lines, but these are used to provide some effect for the digital clock.) You can change the equations dynamically to make, for example, the clock goes backward. The variables are accessible to the user, so learning about the clock, such as angles and rate, etc. can be done from this project.
-- Yoshiki
There is a bug. If the digits in the analog clock is truncated, press "resetResult" button.