I will be in Japan for a week next month. I will be meeting a friend there but would like to use a mobile phone so i can meet up with him. What are my options? Do you usualy unlock UK phones and get a cheap sim? I don't speak any Japanese by the way.
Your best bet is to get a rental Japanese phone at the airport when you arrive. Usually near the exit, after customs, there are counters for buses trains and just near there, you will find a rental center run by one of the cell phone companies. I believe you can get a SIM card, depending on your phone. Otherwise, you can get a regular Japanese flip phone to use while you are here.
I'll agree with TS above on this. When I have visitors from overseas in Japan, I recommend them pick up a SIM card or a rental phone at Narita when they arrive. Some choose to pay the roaming fees with their original phone, but to each his own. Here is a guide of phone services at Narita: Airport Guide : Cellular Phone Rental | NARITA INTERNATIONAL AIRPORT OFFICIAL WEBSITE Haneda as well: Internet and Cell Phone Rentals | Haneda Airport International Terminal
Not sure... is it easier now for foreigners to buy a SIM Card or Cellphone? Last time I tried it was when I just arrived in Japan and it was impossible without my Alien Registration Card. After that though no problem (except the language barrier in some stores though that's more my own problem as I was the one not speaking japanese). The rental option is a good idea and not too expensive. Alternatively your friend could meet you at the hotel or you can do SMS from your international cellphone, that should keep roaming costs at a minimum.
If you have an unlocked smartphone (like an iPhone) you can get a b-mobile data-only SIM from Yodobashi or elsewhere for MUCH cheaper than renting a phone or SIM from the airport, and then just use Skype with it. You still can't buy a SIM or cellphone with a Japanese phone number without an alien registration card.