Very happy so far with our tech setup and I should share some aspects now and detail them elsewhere in case others want to follow this approach.
Before leaving I organized to get a micro sim for my iPhone from a company called iPhoneTrip.com
They offer a sim with unlimited data for $12 per day which is very reasonable for unlimited international roaming.
So. During the day this sim lives in my iPhone and I can use email, gps, Internet, connected apps etc. Basically I feel at home :) and I know how much my data will cost me... All good. I got the sim in Sydney thanks to Alan who collected a parcel and saved the $55 mail out. And it worked in Sydney. And worked in Tokyo. International roaming is no longer arcane magic but knowing how much it will cost you is a nice change.
So one iPhone connected is nice and roaming is nice and a flat fee is nice but I wanted more. I wanted to make a hot spot so I could share my nice unlimited Internet with my other devices.
Devices. I think we have brought with us 5 devices with wireless capability :) ... Yes I know I have a problem but I like living in the future and in the cloud so bite me.
So anyway here we are at 6:54 in a hotel in Shibuya and we have 3 devices blogging at the same time. My MacBook Air and an iPad and I'm typing this on my iPhone.
No tethering and no jailbreak needed.
The magic is in my Huawei 524e PocketWifi. I put my Unlimited data sim into it and abracadabra I can share that unlimitedness.
Knowing the incantation to make the PocketWifi work is advanced level thaumaturgy but the principle is simple and pretty awesome in practice.
I will post more details on what you need to do that device to make it work soon. Basically you unlock it and give it the right apn settings.