cell phone options in jp?

i'm in shinjuku now, plan to stay until end of march. i'd like to get a cell phone. any recommendations? should i just get prepaid phone card and rent a phone? or? i'm from california, so i was thinking maybe i can pick up a cool 3g phone that also work in usa... and have it working while in jp as well.

also, anyone know the deal with PHS? in taiwan PHS system is pretty popular as it is very cheap. it has lower radiations than other system. and you do not pay to receive phone calls. PHS system originated in jp. somebody told me it is not so popular as voice service but for data?

any information is appreciated, thank you.

you're only going to be here a short while; if you're thinking of the convenience of having a cell phone here, a rental phone will do. If you want a phone you can use in the states, you'll have to do some more research. I've been told by friends that some softbank and perhaps docomo phones can work in the states, after they are unlocked in, say, Hong Kong.

It seems that when it comes to phone compatablity with Japan, everything is hearsay. I have a lot of friends who said that their phone pimps in the states promised that they would have no problems on Japanese networks, only to be bitterly disappointed when they arrive. Do your homework and you might not suffer the same fate.