Unicode is the magic system used so all the different letters and symbols from languages around the world can be used on a computer. Seriously, its nothing short of amazing (representing over 110 thousand characters)!
And they make for the ultimate geek password!
But only if your website accepts them (unlikely). And if you can type them (doubtful). And if you can remember all the bizarre characters (impossible)!
On the plus side, most desktop and laptop computers will accept them as login passwords. The tricky part is typing them.
Seriously, unicode passwords are more for show than anything else. You'll get more mileage out of pretty much any other style.
Example: ㈒୫❫✤ʁⲮ₪Ǧ
TODO How to type these!