Auto Add Products to Orders

I give a free product with each order, but I need to account for it in my inventory. I have been manually adding the product in the Admin, but I am getting more orders and it is very time consuming because there are about 4 pages to go through when adding just one product to the order. I also add a box to the order so I can account for that in inventory too. :)

So, I would like to know if it's possible and how I could go about adding a product or 2 to each order automatically, without having to manually do it for each order.

Thanks in advance for any helpful suggestions or ideas.