Many of us breathed a sigh of relief when we learned that Apple improved the resizing of columns in column views. Instead of resizing all columns, you can now resize one column without affecting the others. There are times though when I want to revert the old resize behavior. No problem -- just hold the option key as you resize a column.
[robg adds: If my memory isn't failing too badly, I think 10.3 simply reversed the 10.2 behavior - in 10.2, the Option key was used to resize only the current column...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031118162050872