I played a highlands (epic, noble) game with raging barbarians a week or two ago. I didn't have any copper or iron (or horse for that matter) anywhere near my capital and had trouble keeping the barbarian axemen and swordsmen at bay with nothing but archers.
There was one iron that I could see and had a chance of getting before the AI but I had to pretty much kill my whole economy to get it as I needed at least three more cities to get it without leaving big culture gaps between them. I slowly worked my way nearer and eventually managed to get there and what do I see one turn later? "You have discovered a source of iron near Athens."
Yay!
Also I noticed just how good archers are when you use them to the fullest. Stick an archer with guerilla I on top of a hill/forest. After winning one battle he is a guerilla II and can even beat unpromoted swordsmen pretty easily. At 10xp give him the extra strike promotion and watch him laugh at everything that comes to him. The bonuses he gets are: 25% from a five turn fortification, 25% from the hill and 50% from the forest, 25% from the natural archer hill bonus, 20% from guerilla I and 30% more from guerilla II. That's (if I got everything right) a 175% bonus for a strenght 3 unit making him effectively a strenght 8.25 unit

Add to that the first strike archers have and that one extra first strike chance he gets at 10xp (drill I) and he's one fantastic barb killer and incredibly cheap too!
Also noticed just how stupid the barbarians are. If they had just gone around these guys that I had just outside my borders they could have pillaged me to death. Instead they all decided it was more worth it to suicide themselves against my super-archers. Ah well...
Edit: I didn't lose more than five guys against the barbarians the whole game even though they were raging and I played without resources for at least a couple of hundred turns and on top of that one front was always open to attacks as the AI didn't build any cities there.