I started running an open-table game set in the City-State of the World Emperor. We'll see how it goes. Some rank beginners to D&D have come out to play, and this is great, but does come with its own set of challenges:
What grinds character-creation to a halt is asking players to MAKE ANY DECISION. I think this has to do with the amount of information people need before they're willing make a choice. In 3rd edition there are dozens of starting feats available to 1st-level characters (I had to create a 3.5 character on the weekend to play in a friend-of-a-friend's game, and hated every second of it. The choices I mean, not the game itself!). There is no way a brand-new player can sit down and make any sort of informed decision about his feat choices on the day of play. He needs to take the book home and study it. Bleah!
Veterans with a given ruleset are fine here, but there is also information about the setting that must be considered, and this varies from DM to DM and game to game. Even one-axis alignment (law, chaos, neutrality) is too much setting info to absorb for some people I know to make a decision! Forget about adding complexity to PC races beyond "I'm a dwarf." You're going to hear that Scots accent whether you like it or not.
In the Wilderlands, a human character's origin might actually matter later on, but all cultures and races seem interchangeable at first with only short descriptive blurb. Thus I must force players to roll on a table. If they don't like what they get, they must pick a different option right away, and we can move along to the game itself!
EDIT: after James Mishler's great comment (thanks mate), I thought I should re-write these tables in alphabetical order, to better accord with his descriptions.
Human types in VIRIDISTAN (d%)
Of course distributions will vary based on location, population and political concerns. On the edge of the world, things are different, and it might look like this:
Human types in LAND'S END (d%)
For Wilderlands vets: I have omitted the Gishmesh and Karakhan because I decided that continent is a foreign and mysterious place known to very few. PCs being from there would squash that. Yes the game world does "shrink," but it's pretty huge to start with. The Land's End group have only ranged about 35 miles from town so far!
If a player already has an idea for their character there is no need to roll, but now I have this lying around should the need arise.