I just got an email containing the following instructions. I can not vouch for the authenticity of the flight number but it would be weird if it was.
Maybe someone was bored and just made up this story

Open up a blank document in Microsoft Word.
In capitals, type Q33 NY
Thats the flight number of the first plane to hit the World Trade Center.
Then highlight it and change the font size to 72.
Then change the font to Wingdings.
Freaky or what ?!!!