As i know this SO505I is produced by NTT Docomo in Japan and the phone is locked by NTT. It can be only used by Docomo's user in Japan. It doesn't like the phone in HK which you can change to a new one by using your old SIM card. No matter you change the frequency or not, you can't use it outside japan without joining this mobile company.
If any one knows any method to use it by other way, I would also want to know.
>Dickson You are 60% right. Most of the Japanese here using old system. But 3G service started in this spring. The network is still very poor and not so many people want to use it. Some companies has sim cards cell phones, but those cards can be only used for their own service. USELESS!!