You can hurl your shield as a deadly missile, turning it from a defensive item to a crushing, thrown weapon.

<php>echo “<b>Prerequisites:</b>”;</php> Improved Shield Bash, BAB +9
<php>echo “<b>Benefit:</b>”;</php> You can wield your light shield or heavy shield as a thrown weapon with a range increment of 20 feet. The shield deals damage as normal for its size (see Table 7–5, PH 116), and is treated as a heavy thrown weapon. In addition, if you successfully strike a foe in this manner, you may initiate a trip attempt. You lose your size bonus (though not a size penalty) on your CMB check. If you fail the trip attempt, your opponent cannot try to trip you in return. You cannot throw a tower shield. You can throw a buckler, but it does no trip an opponent.