This is interesting: "Free wifi for Wellington"... Users will be disconnected after two hours, but can login again.
I personally would limit to one hour each time. They are also blocking p2p applications (rightly so).
{MOD EDIT : SP : Moved to a more appropriate forum ;-) }
{MOD EDIT : SP : Added "Trade Me" to the title to differentiate from the NZ Wireless thread found here http://www.geekzone.co.nz/forums.asp?forumid=42&topicid=71739}