Monte - the sheer number of items with potential to trigger the coming slide is weird.
One that I've seen, once, hasn't yet been covered on this site (and is rarely recognized elsewhere) is a severe weather impact occurring in untimely manner.
On the night of Thursday October 15th, 1987, a 250yr storm came ashore in S. England at 10.30 pm. It was heading NE, and was gone off the E coast by 5am next morning. 4ft oaks were plucked out of the ground, spun, and layed down 20yds away. 4 MT of trunks were thrown (plus root plates & crowns) pretty much closing the roads over large areas.
London got the fringe of it and was a mess, but working. The Stock Exchange opened as usual, and then closed after 15 mins, as it was realized that only a handful of brokers were able to commute. The rest were stuck in their smart country homes.
It was the first working day lost in the Exchange since the hight of the Blitz.
The timing was unfortunate as there had been really bad falls in both New York & Tokio Exchanges on Thursday, to which London couldn't respond, that were followed by worse falls in both exchanges on the Friday.
Come Monday morning, the London brokers were in, knowing they had just a few hours to get their prices down to cover 4 bad sessions before New York opened. They dumped their stocks in panic.
When New York and then Tokio opened, they took their lead from London, and panicked. There was £60Bn wiped off UK shares that day, which became known as the crash of '87.
What the storm did was to convert an overpriced market, whose brokers knew it needed a serious correction, into a chaotic collapse of confidence causing a full-blown global share-price crash.
The stom's timing may seem like a very far chance in itself, and an even further chance of there being a repeat - lightening doesn't strike twice in the same place - but, given that hurricane Jeanne has chosen to follow a near identical path into Florida as Frances a month ago, this folk legend may not be applicable.
To get to the point of this over-long post, with a system stressed by so many different factors, together with the profound cultural shock of increasingly open professional discussion of impending peak oil, I suggest that it could be any one of a number of pretty random factors that triggers a sudden collapse of confidence in the status quo.
In that event, the last normal day's production would very likely be Peak Oil, as a few years of recession would further deplete oil stocks before global demand recovered (if it recovered), allowing only a reduced maximum daily supply. Thus Peak Oil would have been caused not by military action or politicking over the oil fields, but by a loss of confidence in an elite cadre of the system's financial management.