>I have never used a thermometer in an application before. (I know, I know, you could say something really nasty here . . . but resist the urge and read on) - I need to run it against a process that takes about four minutes. What's the best way to accomplish this?

If the process is against a file, divide 100 by the #/records in the file and that gives you a value to increment each time a record is processed. If there's thousands of records or so many that the thermo bar updating slows down the process, only update when the thermo value is evenly divisible by 1's, 2's or 3's whatever your preference.

If it's multiple processes, make a best guess of time for each process and update the thermometer by an appropriate value at the end of each process.