It's probably way too late to implement but I REALLY like the idea of single tile improvments that are generated like great people but are placed like resource improvments:

Examples:

You build a "fertilizer factory" in one of your cities - every turn it generates a certain number of improvement points - when some predetermined threshold of points is reached a fertilzer truck (or whatever ) is created. When sent to a tile with a worker it permanently improves that ONE tile to +1:food:

You could have other possibilites for food (orchards +1:food: on a forested tile -etc,etc)

Similarly there could be single tile improvements for mines (strip mine +1:hammers: to a preexisting mined hill)

Basically I'm looking for a way to specialize/improve a city more specifically in exchange for an investment in hammers throughout the Civ. I hate when I know I could work another mine IF ONLY I could sqeeze 1 more food out of the region.

I realize that there has to be limits - basically I would expect that the tradeoff in hammers to benefit would be unfavorable (in my above example a fertilizer factory might cost 100 :hammers: and generate a fertilizer unit ever 20 turns or so - for 1 food over the course of the game it doesnt make it a no-brainer investment, but the added flexibility that these types of improvements would offer would be amazing IMHO.

Interesting, but involves to much mirco manging for me

Cool concept.

It would also make the areas around cities unique so taht you don't have to look at the same building styles.

It could be integrated as random events - such as establishing the International Rice Research Institute (IRRI) in one of your farm tiles which give the surrounding tiles a bonus on food production, or discovering a huge gold vein on a hill which you've mined.

Interesting, but involves to much micro manging for meAgreed. To me this qualifies as one of the things that Soren said they went out of their way to keep out, in some interview he gave. Isn't the "fertilizer truck" basically pollution in reverse? I think the general idea of fertilizer is already incorporated/abstracted into the biology tech. What you are asking for is granted automatically via tech for many other improvements (+1 coin to watermill, etc), you're proposing deviating from the consistent design model of the game.

A city should have a max of one of these special events, like the IRRI - the fertilizer thing would be way to imba. A random event could grant bonuses like the "this city recieves +1:food: from working rice from IRRI - which would then only appear in cities with rice in their BFC to prevent waste of these unique things. There should be more of these the greater the map.