Marginalmente menos irritante é usar PlainClip :
Plain Clip is a tiny Mac OS X application which will remove formatting from text which is on the clipboard. It's designed as a faceless application (i.e.: no graphical user interface, with the exception of the preferences window), which makes it ideal for triggering it from a hotkey / launcher applications such as Spark or LaunchBar. For users of such tools, Plain Clip offers a way to invoke it with a shell command, which makes it possible to emulate a “Cmd-V” / “Paste” keyboard shortcut after the clipboard’s content has been converted.