WARNING!!!
Just to warn people wanting to walk along the Queen Charlotte Track at Picton. There are notices around Picton advising people that there is now a $2NZ charge for ALL walkers on the Queen Charlotte Track. This notice is appearing in the Tourist Information Centres, in hostels and around the town.
I have checked with both the Tourist Centre and the Department of Conservation and this charge is NOT compulsory, and is only voluntary. The notices give the impression that the charge is an official charge, and that it is compulsory, but it is only a VOLUNTARY charge. You do NOT have to pay it if you do not want to.
It is a sad reflection on the way that things are going in New Zealand, more cases now of places trying to rip tourists off, something that was very rare here a few years ago. Sad to see changes like this.
So just to repeat, if you are doing the Queen Charlotte Track and are asked to pay $2 charge, that you do NOT have to pay if you do not want to.

Maybe you could also explain the purpose of this charge and why we should, or we shouldn't, pay it.

From what I was told, the charge it to pay for toilets on the track. If they are going to go for a 'user pays' system, then charge those people that use the toilets, but others that only do a walk of a few hours should not have to pay. The way that they have introduced this charge, and the way that they are trying to make it look compulsory is not good. By all means let people make VOLUNTARY contributions if they wish, but to pretend that this charge is a legal, compulsory charge is not on.
Once upon a time, NZ was a relaxed, honest place, but things are changing. Do you also know about the $5 'charge' at the Kewarau Bridge. Again, this is made to look like a compulsory charge but there is a public right of way over the bridge. Tourists that do not know may believe that they have to pay $5 to watch the bungy jumping, but legally, they do not.
Sadly, there are increasing cases of this sort of treatment against tourists. This is not a change for the better.

Two Whole Dollars! WOWEE! There is a cost to trail maintenance, at least here in the States. If 2 bucks keeps a trail or track open I think it's a small price.

Just to clarify, as you seem to have missed the point. The charge is NOT an official charge, and is NOT a Department of Conservation charge. I object to these other people trying to make others believe that this is an official, compulsory charge.
I would like to repeat that it is neither an official charge nor compulsory. By all means, have a donation system, but it is wrong to try and force people to pay for something that is not compulsory.
In reply to radson, if advising other travellers about a false charge makes me an idiot, then I am happy to be one.

Have a look also at the comments on the main LP New Zealand section for more on this one...

Get over it. So what if you paid two whole dollars? It's hardly a rip off. You can't even get a cup of coffee for that much in NZ.
If a $2 charge is all you're worried about then you're pretty lucky...

It probably cost two dollars to post the OP and replies. If the money goes towards maintainence of the toilets, meaning that people won't crap along the side of the path, then what's the problem? Come on - I pay tonnes of cash per year in tax to educate kids that I don't have, and I have no complaints about it. So why shouldn't someone who walks a few hours on the track pay all of $2 to help maintain infrastructure, even if they're not going to use that particular toilet? This is incredibly petty.