Coupon Code Box in Cart

Hi Guys

Can anyone advise me if its possible to have a coupon code box with apply button in the shopping cart area of a website rather than on the last page of checkout.

We have has numerous customers ask where they enter a discount code. Some try and enter a discount code in the gift certificate box. I know the text can be changed and in our case has to reflect that its not the box to enter a discount code in. However some customers still enter in this box.

I am also not referring to passing a discount code in the URL (although I assume it would need to be passed from the cart to checkout once entered), whilst handy what we really would like to do is add a discount/coupon code box in the checkout so the customer can apply the code there an then and see it on the order before even going anywhere near the checkout.