Currently happens in Auckland and Wellington and is proposed for Hamilton. A few other cities have previously held it.
The concept is basically once a week a bunch of people go out and get a curry dinner. At the end of the night the bill is divided evenly between all attendees.
NZNOG'ers in Wellington are a big fan of this. In Wellington they hold it every week in the same place, Auckland holds it every second week in a different place.
GeekLunchOnWednesdays was a similar concept, but lower maintenance.
One page links to ThursdayNightCurry:
Hamilton