It seems to me the people who need the most reminding of what happened that day are elected officials in Washington D.C. who are exploiting this day in the most disrespectful manner...
A memorial plaque over the doors to both the house and senate chambers would be most appropriate in my opinion...
And putting one up to the entrance to the Oval Office might be a nice thing as well...
Those to be never taken down...Ever...
WAHOO! That is THE best answer so far!
Profound in fact!