Artistic said: theres a can IN the chicken??? Yup. It's normally called beer can chicken, but you can use soda/pop, or if you have a empty soup can with water or broth, that works too. It goes into the cavity of the chicken, which helps it stay upright. It gets cooked evenly with the liquid in the can helping to add flavor.
I normally use chicken broth with salt, pepper, and poultry seasoning in the liquid, as well as seasoned under the skin of the chicken. It's a fair bit of work, but worth the effort.