[QUOTE=Vaitork
@stanav: Since I need the user to input quite a bit of data (it's an engineering simulation program after all), I can't have a substitute for TextBoxes.
[/QUOTE]
NumericUpDown controls fit perfectly in your situation. They still allow the users to type in values just like textboxes while having the bonus spinning buttons to increment/decrement the values at mouse clicks. Besides, you don't have to worry about users typing in non-numeric data... And finally, I don't see any reasons why numbericUpDown controls can slow down data entry comparing to textboxes. My programming philosophy is: always try to use the right tool for the job. It will greatly reduce your efforts to find "workarounds" and also add stability to your application.