I was surprised to only learn this maintenance tip now, especially because pref file corruption is a relatively common cause of OS X problems. I don't recall this being a part of any of the usual maintenance utilities, yet it's a shell utility that's present in 10.3.9 (at least).
Like all sudo commands you must run it from an administrator account (sudo gives admin users transient superuser/root like powers)
sudo plutil ~/Library/Preferences/*.plist -sPlutil checks all the preferences inside your User folder for any corruption. The -s handle in the command suppresses any reporting of preferences that check out, so only ones with errors show up.
I would usually delete any pref file that failed this test.