Community Exchange System (CES) website.
So if you're in or near Wellington, and have signed up (or want to) with the CES here - I'm just as happy to trade using these 'green dollars' as with ordinary money.
I'm also happy to answer questions about my experiences with the CES so far (which have all been good). You can email me, Johanna, at email@example.com
I wrote more about alternative online currency and trading systems on my other blog a wee while ago, too.