JCI has released a new SIM card targeting overseas visitors. Currently, there is only a U300 version available. (EDIT: This means it is unlimited data but at a 300 kbps speed.) I imagine that several other versions, such as a 1 GB Flat Rate may also be in the works.
Similar to the standard U300, this provides an unlimited, symmetrical 300 kbps "best effort" connection. Regular-size and micro SIMs are available. The SIM card does not support streaming media or VoIP such as skype. The primary differences between this and the regular version are:
- ¥2,980 for 30 days (Not rechargeable)
- An English-language web page.
- English-language support.
- Pre-activation (no need to call with a Japanese mobile phone to have it activated after arrival).
- Pre paid by credit card only (No COD).
- Valid for 30 days with no extension.
The SIM card is activated on the second day after shipping, which starts the 30 day clock. There are no refunds, even if the SIM card gets lost in the mail or delivery is otherwise delayed. While that's not quite ideal, there really are not any other options, since the card arrives with an active connection.
Overseas phones must 1) be UNLOCKED and 2) support UMTS-2100 MHz, which is the primary European and Australian/New Zealand frequency. This will work with unlocked iPhones. The unlocked US T-Mobile phones I've used support 2100 MHz. Most AT&T android phones will not work with this SIM card.
See here for a list of all (well, most) b-mobile SIM products and here for information on battery life.
A NOTE ON FREQUENCIES
This SIM card relies on a 800 MHz 3G connection any many rural, mountainous area. This is known as the FOMA Plus Area. 800 MHz is not used, as far as I am aware, outside of Japan. As such, users of b-mobile SIMs with overseas phones are more likely to have little or no signal when waaaay back in the mountains. As for everyday use, there are typically few issues.