When the "Word in Business" conference came to the Anatole Hotel in Dallas every Thanksgiving weekend, we locals had the "privilege" of doing all the gruntwork - unloading the trucks, setting up the rooms, etc. At the end we loaded everything back up. All on our own time, of course. I think I even took an unpaid day off from work since we were highly "encouraged" to help.
We were required to wear steel toed boots at our cost. And woe be unto you if you screwed up somewhere while you were slaving away.