I used to have a pixie cut and I have a fairly round face, it worked really well because the way it was cut elongated my face and defined my cheekbones. It aged me a lot though, before I got my hair cut I looked 17, after - about 24! I had to be so careful with the makeup!
Now I'm just trying to grow some really nice long carefree hair, I've had so many short haircuts, it's time to be an uber girl.
[EDIT] Found an old photo! I think this was after a night out on town Easter weekend '07 lol.