-Stop the Help Viewer from Floating Over Other Windows

The Mac Help Viewer always forces itself on top, and that's incredibly annoying when you're trying to troubleshoot. That's easy to disable though: defaults write com.apple.helpviewer DevMode -bool true
Of course, the list above isn't even close to everything. We've talked about plenty of other things you can do with Terminal, so start digging in. If you want to tweak some more with a interface, OnyX is our favorite tool.