AsheLeopard's post reminded me of the gingerbread house I made with a friend last winter. It was not as professional looking as AsheLeopard's, but I was still really proud of the end result.
We first designed the house with posterboard and then set out making the gingerbread. We used jolly ranchers and life savers for the windows. We then piped on the royal icing details. I also put a strand of Christmas lights inside the house so that the windows looked like they lit up. The only problem with the whole project was that I live in humid Florida, so the windows soon began to weep (run down the whole house) and the gingerbread got really soft in only a few days.
Here is the front of the house
Side of the house
And finally, the back of the house
Thanks for looking!