I learned my ladder lesson inside (luckily). Trying to use the "this is not a step" as a step when the whole ladder just tipped over and i was slammed into the floor. My whole body hurt for a week.

Outside...the most dangerous thing i have had to do is climb up these icy rebar "ladder rungs" to the very top (I only had to climb the last story) of a skyscraper to mount my XM antenna...while it was snowing!