I just thought I'd change this thread a little, since it was originally focused on YAJ! But sometimes you wish to buy items from the US (eBay) and sellers refuse to ship international.
I signed up for Australia Post's (ShopMate) service a while back but haven't had to use it for anything until I recently found a pair of Solex/Mikuni carbs listed as 40s, but 1 carb was actually a 44mm carb. I managed to grab the pair for $200 USD. However the seller didn't originally have the option to ship to Australia. He said he could post to Australia for about $60 USD. However I decided to give shop mate a go.
Long story short, it cost me about $20 to send to the depot/warehouse and another $100 to ship here. So I paid about a $40 premium to use the service.
In future I'll be pushing sellers to send direct if possible, but failing that and if an item is absolutely essential you can use Shop Mate to get the item to you indirectly.
The only other caveat is that the ShopMate declaration form doesn't really have automotive categories, so I had to choose "accessories" and I listed the items as automotive part, intake in the description.