On the Our Wee Country website, there is a fun link to people all around the world flying the Northern Ireland flag and/or the football flag: http://troopingthecolours.com/photos/
I can't see any from the Philippines yet! :)
Perhaps in your flag section, you could add that the Northern Ireland flag is still officially used at some sporting occasions when Northern Ireland teams play - e.g. the Northern Ireland football team or at the Commonwealth Games.
http://www.thecgf.com/countries/intro.asp?loc=NIR
But you are correct, the official flag to fly from buildings is the British Union flag like the rest of the UK.
Thank you for putting together this website - it's great! :)