Prepaid data sim for tourist now in Japan?

Desperately in search of a prepaid data sim for and unlocked iPhone 4. I live in Nishi-Shinjuku near Shinjuku station and will be here for 63 days. Unable to connect with eConnect due to a PayPal issue (credit cards). I have a temporary visitor stamp, and I would prefer already set up, but I'll take what I can get (within reason).
Any help would be appreciated!
Many thanks!

Not sure what your problem is, most SIM cards sellers can ship to any address in Japan...

Many thanks, Firas. I was hoping to walk into a place and have it done,but I thing that's for residents only. Does anyone know of a short list of providers? Iknow of b-mobile and sakura.
Many thanks again!

There is also cdjapan: http://rental.cdjapan.co.jp/

However, for two months a regular b-mobile SIM (i.e., not one aimed at tourists) will probably be more advantageaous, but everything is in Japanese only: http://www.bmobile.ne.jp/bmsim/index.html

I always get the b-mobile visitor sim for when my friends come to visit me.

http://www.bmobile.ne.jp/english/

1 GB or 30 days (maybe they changed very recently to 14 days?). You need to get your hands on a Japanese cell phone to activate the card - The call is for free and every hotel will do it, but the staff like Yodobashi Camera will not do it.

I forgot there is also So-Net SIMs, which are apparently sold also in physical stores: http://www.so-net.ne.jp/prepaid/en/