I had an idea a while back...
There are a few theories about the shifting magnetic poles, and how the world might shift off it's axis and rotate in a new way if they become too far out of alignment. The movie 2012 touched on this a bit, and at least one theory about Atlantis uses this as a hypothesis.
As a result I've considered the idea a few times.
What would the map of the world look like if you pplaced the north pole at an arbitrary point on the globe, placed a south pole diametrically opposite, and then spun the world on a new axis as defined by these points.
It either of the pole locations was on land then it would become locked in polar ice (much like Antarctica), if it were close to land then there would probably be an ice-shelf packed with glaciers along the shoreline. Much like the northern coasts of Russia and Canada.
A map of the world drawn from the perspective of this new spin would probably look vaguely familiar in places, but dramatically different in others. After a few hundred years you'd note changes in the vegetation. With rain tending to fall toward the east of mountain ranges while a rain-shadow of dry land falls to the west. Imagine enough of a tilt to cause the Amazon rainforest to now become a vast desert, while the rolling desert plains of Western Australia and Africa might become a lush and fertile ecology.
I've looked for programs that might redraw the map from a tilted perspective, but haven't met with any success so far. I haven't been expecting such programs to account for ecological changes, I've just been looking for coastline manipulations. But no luck. I didn't think I was after anything that was overly revolutionary (no pun intended).
I'm considering the idea of drawing up a few sample maps, perhaps to use as the basis for a new project. It's just one of many ideas at the moment.