Rental SIM Japan + iPhone 3G

I am curious about rental SIM cards in Japan. How does this work, will you pay a phone bill when returning the SIM card or will it need to be pre-paid?

Will calling toll free international numbers with the SIM will it still cost? Will emergency numbers cost?

Will my iPhone 3G work with it and in Japan?

I am curious about rental SIM cards in Japan. How does this work, will you pay a phone bill when returning the SIM card or will it need to be pre-paid?

Both prepaid and post paid (rental) SIM are available. With prepaid you pay in advance. With rental sims you are presented with an itemized bill some time after you return the phone.

Will calling toll free international numbers with the SIM will it still cost?

Depends, cell phones cannot call some toll free numbers.

Will emergency numbers cost?

No

Will my iPhone 3G work with it and in Japan?

Only if it is unlocked.

Thank you.
You wouldn't know where I can find out what toll free numbers are not able to call from a cell phone in Japan?

I was looking it up and it seems that the restrictions on calling toll free lines have changed so you should be able to call most toll free numbers from a cell. If not you could use a public payphone instead.

But a public payphone could be free using intl and domestic toll free numbers?

But a public payphone could be free using intl and domestic toll free numbers?

Yes for domestic, but in most cases, toll free numbers are not free when called from abroad so probably no on international toll free numbers.

There is something called SOS Intl' located in Denmark, supposed to be either toll free or able to recieve collect calls or whatever it is called. I have no clue though if it would be free calling from Japan from either land line or Japanese cell phone though.