I think a number of you will be interested but I found a fantastic page http://spectrumonline.med.govt.nz/ which details all companies who have a registered radio frequency in NZ, plus the frequencies etc.
In there there is the "Spectrum Search Lite" which is an access database that has every transmitter that is registered with them. Plus the Lat/Long in different tables. After a bit of fun with Access I extracted out what I wanted.
So I extracted all the 2067.5Mhz registered frequencies (which is what Woosh uses) and matched them up against the Lat/Long so now I have a list of every location that there is a transmiter, built a quick and dirty Google Maps page with the results.
To be found at: http://wooshinfo.googlepages.com/locations.html
If there are better google maps person out that that could write nicer code I would love to see it.
(moderator edit (BG) - Added hyperlinks)