Any ideas where I can book cheap flights to Oz with a stop over in the US or Tokyo?

I want to book flights to Australia for the christmas and new year period. I was hoping to do it with a stop over in either New York, Las Vegas, Niagra or Tokyo on the way there (between about 15th and 20th December). I only want flights, no accomodation. Do you know any good websites or companies I can phone to find multistop trips or round the world tickets. Have you done it and got any tips on keeping the cost down? Any information on the entire process would be greatly appreciated.Any ideas where I can book cheap flights to Oz with a stop over in the US or Tokyo?
Christmas will be expensive, it'll be impossible to keep down the costs. New Year is Japan's big holiday so the flights from there will be ultra expensive.
have u tryed that travelsupermarket.com. apparently it's great for things like that...good luc xxxAny ideas where I can book cheap flights to Oz with a stop over in the US or Tokyo?
try airline-network.co.uk or travelbag.co.uk phone COLIN SALT on 0870 814 2635 @ travelbag he is very helpfull , and HAGGLE over the price %26amp; you will get a good deal
flight centre is a good one. you can also try zuji.com for some great deals.
try amazon.com,or makemytrip.com
if you set off now you could walk most of the way saving you loads.
If you go at xmas and go the long way round, its bound to be a lot more expensive, no matter how early you book.
Try Flightcentre. We booked our round the world trip with them. Very good.

You could also try the airlines direct now as you will be booking in advance there may be discount.
Expedia.com