My household was a minor affair, we had little candles in the shape of the WTC on the dining room table. We would thank George Bush for the Patriot Act and then light the candles. We had to be good, because George Bush was always watching us with the Patriot Act, but if we were good, we'd get little pilot's wings pins.
The rich kids in my neighborhood had more elaborate plans. They had full on model WTC towers. If they were good, there would be RC planes under the towers on 9/11 morning. They were always showing me the cool videos when they destroyed the towers.
As I mentioned in the other thread, we get a pair of 9/11 trees every year. The kids make paper people that they decorate and hang as ornaments. Then, on 9/11, we burn the trees down using thermite to symbolize the jet fuel that melted the steel beams.