What do kittens use gold for?

There's a lot of things gold is useful for. To me, it's:

• Titanium (which it sounds like you're not at yet) through trades with the Zebras
• Spices through constant trades. Note that spices, being a luxury resource, give you 10% happiness bonus, so it makes everything faster.
• Temples also increase happiness and use gold.

So it boils down to titanium and happiness. Go figure, gold fuels industry and happiness, just like in real life!!

I have 38 smelters going right now with 65 kittens. I fire off a trade (with my auto script) every 75 seconds. (Actually, 70-80 seconds since it runs every 10 seconds and fires off a trade if i'm at over 95% capacity gold...)

The script is below. Make sure you have visited the trade tab, or it will never have generated the button to press. :O And sometimes it dies, so keep an eye on it, or it will just spend your gold and slabs. Yikes.

var trade = function(name) {
    console.log('trading with ' + name);
    var faction = gamePage.diplomacy.get(name);
    if(!faction) return;
    var title = faction.title;

    var panel = gamePage.diplomacyTab.racePanels;
    for(var i = 0; i < panel.length; i++) {
      if(panel[i].name == title) {
        var prices = panel[i].tradeBtn.prices;
        for(var x = 0; x < prices.length; x++) {
          var pool = gamePage.resPool.get(prices[x].name);
          var req = prices[x].val;
          if(pool < req) return;
        }
        panel[i].tradeBtn.payPrice();
        panel[i].tradeBtn.handler();
        return;
      }
    }
}
var autoZebra = function() {
    var gold = gamePage.resPool.get('gold');
    if(gold.value / gold.maxValue > 0.95) {
      var doTrade = true;
      var slabs = gamePage.workshop.getCraft('slab').value;
      if(slabs < 50) {
        doTrade = false;
        var per = 1 + gamePage.bld.getEffect('craftRatio');
        var needed = (50 - slabs) / per;
        needed = Math.round(needed + .6);
        var minerals = needed * 250;
        if(minerals < gamePage.resPool.get('minerals')) {
          gamePage.craft('minerals', needed);
          gamePage.msg('crafted ' + needed + ' slabs for zebra trade');
          doTrade = true;
        }
      }
      if(doTrade) {
        // make sure we have room for the new iron, might as well
        // make free plates if we're going to go over the cap as a result

        var iron = gamePage.resPool.get('iron');
        var ironGained = 1.2 * ((gamePage.bld.getEffect("tradeRatio") + 1) * 300);
        var ironSpace = iron.value - (iron.maxValue - ironGained);
        var platesNeeded = ironSpace / 125;
        platesNeeded = Math.round(platesNeeded + 1.5);
        if(platesNeeded > 1) {
          gamePage.craft('plate', platesNeeded);
          gamePage.msg('crafted ' + platesNeeded + ' plates for zebra trade');
        }
        trade('zebras');
      }
    }
}, 10 * 1000);