I have been considering the idea of building a plug in that would operate like a debug window, in that when opened, you could see the values of certain variables. It would be similar to tailing the log, although not in real time. For my purposes, knowing the value of several variables that change once every five minutes, this limitation would not be a problem.
My thoughts were to model it after the Holiday Virtual Switch, which collects data, formats it and displays the results. This would work perfectly for reading and displaying variable values. Has anyone done anything like this? If so, care to share your code or your insight?
If you were feeling particularly adventurous, you could do it with a JavaScript tab. The tab could poll for variable status and display the results. An advantage of doing it in JavaScript is that you can have as few, or as many, variables being watched as you like.
Perhaps a better starting point is the dataMine plugin.
@futzle: do have a very basic plugin which uses java? I am interested in this, but since I am just a hobby programmer starting of with the datamine plugin as an example is quiet hard for me. :-[