Typical low-level dungeon (The Burning Plague, in fact) with typical kobolds hiding behind cover.
The PCs have previously bashed down the door to get at the kobolds.
Me: The kobolds jabber at you and hurl javelins. You're each struck once for... *rolls dice* 2... and 3 points of damage.
Player: I pick up the door and use it as a shield to block the next volley of javelins.
Me: Er, what's your PC's Strength?
Player: 16.
Me: (glances at Player's Handbook) Okay, you pick up the door.
Player: On my next turn, I rush the kobolds, holding the door out in front of me.
Me: *rolls some dice* You charge. The kobolds squeel in terror, but before they can get out of the way, you squish them against the far wall.
Player: I clean off the door.