Aluminium!

Good grief, I can't even spell it!

If you're not being sarcastic: http://www.worldwidewords.org/articles/aluminium.htm

Now that was fun, thanks. I find it annoying that I am taught to spell a certain way, but then the British keep reinventing spellings with "s" instead of "z" and adding an "i" in there just Americans on their toes.