Personally, I dislike relying on the influence system to capture resources. As it stands now its just to hard to predict the rate of expansion, many times I'll be waiting for my influence to expand, and in the mean while the AI will come by and drop a city next to the resource I wanted to capture.
The only real benefit here is that it give me a nice pretext for war hehe..
In another post I saw an solution involving the use of a "corruption" system, where the more cities you have the harder it becomes to maintain your empire- Its not a bad idea, but it has potential to ruin the fun (Rome: Total War for example).
Maybe the answer is just to make new cities and powerful, advanced buildings require food. That way a player will have to choose between more basic cities, or fewer advanced ones.
Also I've heard talk about treating population as a resource in 1.1? I'm guessing it will work by making a new city use up population of existing cities. I think this would have a similar effect on game play to what I described above.