I also do the leg shaking thing. It's pretty common, actually.
I look out of the window every time I hear a plane going overhead.
I can't eat an apple with breakfast (it's weird).
(I used to do this, not anymore): Whenever somebody was speaking, I used to imagine their words typed on a page, or sometimes even TYPING the words. It got really annoying.
I get really annoyed when anyone uses shortcuts (4ever, u, y, etc.), even on MSN.
I have a mouse right next to my laptop, and it's much easier to use, but I still use my touchpad.