I made this map based off of Rhye's 4 civ map. The idea of this map is that there's a lot more room to make good cities, and it balances out areas somewhat. I also made the New World MUCH nicer, hopefully encouraging a lot more racing to get there.
Mainly what I did was:
Change all desert on river tiles to floodplains
Change all desert tiles on water to plains
Move the grassland/tundra line up one, creating more grassland
Moved the tundra/ice line up one, creating more tundra
Added resources to otherwise very poor places for cities
Created passages from the old world to the new world with galleys (on on the side of Europe, the other on the side of Asia).
Added a fake river in Australia, to make it more useful.
Added several sea food resouces
Changed some of the mountain structure in the Panama/Columbia area (now much more accessible)
Made Tibet, Alaska, and much of the Western US a reasonable place to settle
That's more or less it. The effect should be that there are more civs springing up from barbarians, and that there are more places which will be settled. Hopefully this has the effects of emulating a larger map, without actually having one. I am also hoping that this will weaken the advantage of being one of the first civs, and will enable civs which come up in the middle of the game to become the world leader.
Edit: It seems to work in the Play Scenario setting, but not in the Custom Scenario setting. If anyone knows why, or knows how to fix that, please let me know. Thanks.