Feds OK Taser Stun Guns for Airlines  NEW YORK (Reuters) - Taser International Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=TASR.O target=/stocks/quickinfo/fullquote"&gt;TASR.O&lt;/A&gt; on  Monday said it won U.S. government approval to use its stun  guns on some commercial airline flights to protect passengers  from potential harm.