What is gold good for?

I'm not really a Minecraft player, but a quick glance at the wiki indicates that you should (like with other metals) first smelt raw gold ore in to Gold Ingots, using a furnace.

These ingots can then be used to craft weapons and armour (which you don't want), but also used to create Clocks and Powered Rail.

You can also combine 9 ingots in to a Gold Block, these can then be used for construction (if you want a nice golden house or something) or these ingots can then be used to craft a Golden Apple, which instantly restores your health.

Given the supposed rare nature of Gold within the game and the items you can create with it, I would presume Gold's most important usage is in the creation of Powered Rail, which (from what I see here) vastly increases your construction options with mine carts.

You can use it to create:

• gold blocks for decoration or for a beacon base

• powered rails for a massive minecart empire.

• a clock
• gold nuggets that make golden apples, carrots, melons and fireworks.

With the new villager trading feature that was added in version 1.3 you can now buy and sell items using emeralds as currency. All of the 5 villager types have a chance that they may offer to buy gold from you, but a Blacksmith is more likely to offer this trading option.

So, if you don't use your gold for much else, I'd say hold on to it until you find a villager who will buy it from you. It's a good way to amass emeralds.