Volunteer in Fiji

I'll be in Fiji for 10 days in early December
As I've heard some stories about bad weather in that time of year I was wondering if there are places where I can do some volunteerwork.
I'm thinking of a school or an orphanage thats happy with a foreigner that pops in for a day or so.
Not all schools and orphanages like this (I know) but sometimes they do.

I'm also raising money so I can spend it on good causes when I see one. are there any in Fiji? I prefer small projects where al the money goes to the project and not into someones pocket.

Being the Southern hemisphere, you will find most schools are either on holidays or winding down to holidays in December, so it would not be a good time to volunteer in a school, unless you wanted to do building or repair work.
A good place to start looking for volunteer work would be the churches - the biggest in Fiji is Methodist, but there are other denominations. Most charity work comes under one or other of them in the islands.