In the past, I provided some ideas for a world where the geomagnetic poles shifted of their axis, causing a huge electromagnetic pulse like the spinning of a huge magnet, generating massive electrical energy that simply obliterates the electronics of the world.
The aftermath of this catastrophe was a world where the orbit destabilised and the planet now spun on a new axis, with a new randomised polar point. To illustrate this, I generated a map with a north pole in Madagascar.
This is a project that has sat orphaned for a while, but I've decided in recent months that it would make a good fit with the Walkabout setting.
I'm now going though the various types of catastrophes that might befall different parts of the world when the global tilt-shift occurs...including seismic events, pandemics, nuclear fallout and anything else that might cause panic on a global level. I'm also researching as much as I can about the continent of Antarctica beneath the ice cap.
There's some interesting stuff happening down there. Even this week (as I write this post in early February 2012), there are Russian scientists drilling into the depths of the ice to reach an unfrozen lake that has been encased in ice for millennia. In the real world, these scientists have gone ominously silent.
I'm becoming very tempted to write an entire world book, perhaps an atlas of a post apocalyptic earth. No stats, no rpg rules at all...just an artifact from a possible post-apocalyptic future. A second book would be the Walkabout game, detailing what you need to do in order to play in this eerily familiar setting.