Another approach is to look at the SalguaMagentoAddProduct extension  https://github.com/salgua/SalguaMagentoAddProduct it provides the ability to do what you are looking for.

Add product and coupon to cart together
One specific creature from the Commonwealth Saga has caught my interest -- Tochee. My imagination is really bad, and I can not hold all the descriptive details in mind at once. I have tried to find some illustration, but unsuccessfully. All I found was this non-Tochee :

http://www.flickr.com/photos/rickpickett/7464577876/

Can anyone help me by pointing me in the right direction?

Off-topic: I would highly appreciate if anybody could make a drawing from the descriptions given in the Tochee link :o)
