I don't know which OS version this first appeared in, but I've never read about it before and just found this out while playing in 10.2. If you use a mouse with a scroll wheel, press shift while scrolling in a Finder window. The content will scroll to the left and right while pressing shift and using the wheel! This is very useful in column view!
By the way, it also works in MS Excel, but so far I didn't found any other program that supports this feature.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020828092835955