You might like to grab the code that Bob helped me with for the weather station barometer/thermometer gauges. 
http://www.squeaksource.com/WeatherStation.html
Oh, wait, the dial stuff is RotaryDialMorph which is in Morphic-Extras-Widgets which ought to be in the trunk image for now.

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
Useful random insult:- A gross ignoramus -- 144 times worse than an ordinary ignoramus.