If you`ve got a headache try some tramping in Mount Aspiring National Park.
As its name suggests it can help you feel better by listening the sound of water falling down on the rocks.
Anyway, if it doesn`t work after looking at the advice you`ll forget it :-)
At first I was not thinking about staying in Wanaka because time flies and there is not much of it available :-( But it is a pleasant place to hang out or to look at the twilight in front of the lake. It happens about 9 p.m. in this period of the year :-)