I have 3 large flags in my room, A Canadian, Europian Union, and the Union Jack.
For some reason I was looking at the Union Jack today and noticed that the diagnol cross is off center and doens't line up at all.
LOL, I never really noticed this before, so I went on a google search. At first I read some people just saying it was to make it asymetric, so to know which was is up.
But then i finaly found this:
http://users.sisna.com/justinb/ujack.html
Its more of a pinwheel than a diagnol cross. I found it kinda interesting.