Here is the list of phone rental at Narita airport.
http://www.narita-airport.jp/en/guid...st/svc_19.html

Looks like E-Phone, G-Call, JAL ABC all have usb HSPA modem rental. Cost is about 5000-10000 yen 5 days - a week. Not exactly cheap, but still better than any roaming alternatives.

Also found this site http://www.japanmobilerental.com/USB_Modems.html also do rental for 5000 yen a week.

Have anyone try any of these rental service? Do you think I can try to take the SIM card from the modem and put it in my WinMo phone and make it to work? I much rather have data sim card than a USB modem.