illiterate's point about the city limit lines, seen here: http://gtadomain.gtagaming.com/images/sa/offmaplossantos.jpg
is the best one so far. indeed, a city does occupy the top right part of the map, and could be seen from Hanky Panky Point.
Also, another piece of information learned from that is that no city is found in the visible portion of the island to the west. This means that if further country is supposed to separate LS and SF, it must be to the west of LS. There is only one bridge crossing towards where Las Venturas must be, making it much easier to block off for more of the game.
Also, the flat line of coast on the SF island right next to the Panopticon looks suspicously like the edge of a runway bordering water. This places the airport far away from most of the bridges, but still close to the panopticon.
If the airport is there, the Panopticon can look towards Bone County to the north (to the west of Las Venturas, maybe extending most of the way towards the western edge of the map), Flint County to the south/southwest, and the airport.
I remember this piece of information none of us can find the original source of saying that you can drive "up a mountain" and "into" SF. So, the way to make you drive longer through Flint County (sounds like mining and stuff so fits mountains) would be a whole range of mountains/hills/cliffs surrounding the city and airport, and you would have to drive far west after leaving LS to go north past/through the mountains into SF. SF may sit on both sides of a river as tnk originally thought, and on the next body of land that SF's north side sits on, it slowly transitions from green to desert, becoming Bone County, which would extend far east until LV is reached. Now, this leaves Mount Chilliad anywhere in the southwest quarter of the map, which is all country, giving it plenty of space to sit byitself in the middle of nowhere as it does in this picture:
http://gtadomain.gtagaming.com/images/sa/screens/54.jpg
Also, to discount PSM's ideas of where everything is, they also mentioned that the entire map is green, just as the map of LS that Rockstar already released is. That means they could of looked at where the roads were centralized and just guessed which city was which.
I still have no idea how the land right around SF looks, here are some examples.
picture of gant bridge:
http://img78.photobucket.com/albums/v258/t...t/Unknown/8.jpg
another picture of gant bridge proving nonmountainous terrain is on either side of that bridge:
http://gtadomain.gtagaming.com/images/sa/screens/129.jpg
another one that confuses everything:
http://gtadomain.gtagaming.com/images/sa/screens/199.jpg