Im a kiwi also...
I have been listening to JP101 for about a year now and it has really helped me out..
I first went to Japan last year in October an i was freaking out a bit, so i found JP101 on the pod casts, downloaded as much survival phrases as i could and it saved my bacon whilst i was there for 4 months...
backpacked 2 months..
snowboarded 2 months...
well sorry this reply is late because i have only decided today to register onto the site
ka kite e hoa ma
So just one listener from NZ, cool as. I am finding it hard to grasp the idea of speaking in informal, basically I dont understand the conjugation. At the moment I am in a Boys High School in Auckland, I'm learning Japanese at school but it seems to go so slow... We learn all the basics like, where you go, eating, daily routine, time, classroom, housing, sports and hobbies etc. I plan to go to Japan this December for two months and study as a Senior High School student in Kisogawa, do you think that knowing informal is really important? じゃまた
Another kiwi here, have been in Japan for a few years now and listen to JP101 on the way to work. Anyway to answer your question, learning informal is very important if you want to communicate with other students. I doubt they will be speaking formally amongst each other.
not a kiwi.. but i think for speaking informal, one quick way to almost get it is to take the formal phrase, and drop all the particles and all the polite forms of anything... what's left is gonna sound almost similar to the informal phrase.