I used to teach 7th grade and was always looking for creative writing assignments. I used "Letters from a Nut" to teach letter writing. My favorite was the letter from a guy who left his sword in a hotel. Then, I would have the students write a letter about some fictional situation.
Again, I am still watching "CBS Sunday Morning" and came to the section about funny letters from camp. It is called "PS-I hate it here!" Again, what a neat way to teach letter writing. I think the kids would get a laugh out of these funny letters about camp.