I’ve always been really frustrated by the narrow widths of the column view in Mac OS X’s Finder. I’m regularly widening them to see more of the file names, and wishing they stayed wider when I open the next one. So, today I searched for a solution.
In Mac OS 10.4 [and greater] the default width of the Finder’s columns can be changed by option-dragging the column handle to your preferred width. When you close the Finder window and open a new one it will open with the columns sized as you indicated.
It’s so easy to do, it’s almost frightening.