The other answers so far mostly suggest cooling your coffee by putting it in contact with cold things. This is a bad idea because it
- Doesn't increase the rate of cooling a lot initially (approximately by a factor of 2 to 3)
- Does increase the rate of cooling a lot once the coffee is already near room temperature relative to normal cooling, at which point you risk over-cooling your coffee
- Ice cubes will dilute coffee
Instead, I suggest cooling your coffee in a different way. The rate of cooling is proportional to the surface area of the liquid, so increase the surface area of your coffee.
Take your coffee, and poor it into a large pan or container. The container should be as long and wide as possible. This increases surface area. This Pyrex 4-quart baking dish is a pretty good option, and is useful for other lifehacks like the "storing a leftover casserole in your refrigerator" hack (also requires plastic wrap). A bowl is not a good option as the rounded bottom has low surface area. Then wait for it to cool. You can put this near the fan if you want to, which will improve air flow and help mix the coffee, but it isn't strictly necessary.
If that doesn't cool fast enough (as could be a problem if you have to cool a whole pot of coffee and can only afford a small baking dish), take any clean metal silverware you have available and put it in the container prior to pouring the coffee. Ideally you want to have the silverware submerged as much as possible, but still have a small part outside the coffee so that it will stay in contact with the air as well and thus transfer head to the air. For forks and spoons, place them so that the large ends are in the coffee. This does two things. For one, it increases the surface area of the coffee, which is good. But it's doubly effective because metals are also good conductors of heat, and will evacuate the heat from your coffee faster than just air alone.
If that's still not fast enough, in addition, you can take an electric mixer and turn it on at high speed in the coffee. You can also mix with a spoon or whisk, but that's not as effective. The mixer will get air bubbles into the coffee. Don't worry, they won't stay for long, but that increases the surface area further. It also causes circulation, which will lead to a higher rate of evaporative cooling.
Once you finish with that, pour your coffee back into your mug (through a colander to sort out the silverware) and drink. Note that in a pinch, you can combine this method with most of the ice and/or refrigeration methods, but this is not recommended unless your coffee is very hot and you need to drink it very quickly.