I give this warning to anybody on my current players list: look away now. I'm going to reveal the number one secret of the world your future characters will be living on. Loki, SuStel, Arcadian: I mean you folks. :) I'll be putting "players keep out" as a tag on posts like these.
The world is tentatively called "The World of the Twelve Faces". It's not a globe. It's a dodecahedron. I've had all kinds of wonderful and bizarre ideas about how it works (inspired in large part by an article on a cubical earth that I believe Zak S. posted some time ago). I'm taking Zak's 'the underworld connects various surface areas to each other' idea as well.
Each face of the dodecahedron has its own geography, inhabitants, and history. Yes, they're connected via the underworld caverns and such, and occasional migrants from one face to another may be seen, but basically they're isolated from each other. I've only built up the face the player characters will start on: Face Five. I've had a minor brainstorm or two on what and who might inhabit the other faces, and as I've begun scrawling down notes on the faces I've vaguely outlined interesting geographical bits about each.
The geography of each face is heavily influenced by the numbers that appear on the twelve-sided die I hold up whenever I'm pondering the world. (I've become painfully aware that different dice are not only of slightly different sizes, but the numbers are frequently in different places and/or orientations, so I've had to decide on a 'canon' twelve-sider so that I don't confuse or contradict myself. Chessex are my favourite dice, so I'm using my bone coloured one for this purpose, though that pretty light-and-dark blue speckled one on the windowsill is very nice... but different. >.<) Many of the faces sport a deep canyon or crevice of some kind, though in all cases this doesn't look like the number any more. Well, Face Eight might, since it has a superfast-moving river system that looks suspciously like the infinity symbol standing up instead of a central sea like most of the rest of them, in accordance with what I learned about cubical earth.
There'll be more on this stuff later. Hoping to get into a more regular posting schedule around here.