Column width workarounds

I have been looking over the forums looking for answers to the question that nails us all: how do you dynamically resize column widths? MS says: you don't. However, I have heard many people say they have found ways around it. I wonder if anyone might share those with me (and everyone else). Share the wisdom you have gained with those less experienced!
The work-arounds depend on your situation. If you can explain your situation you might get a better answer.