I personally have an American Macbook (white) that uses the 802.11n spec. I've never had a problem in connecting to anyone's wireless network. Most current Macintoshes will use either the "g" or "n" spec. Check with your manufacturer if you have a Windows PC. Any router sold should have these specs listed on the box.
Second, some of you have asked about a more mobile wifi solution. Please visit these links:
patchmonkey wrote:All the major cellular providers provide wireless internet services. That's pretty much your only option at this point, the other wireless services I know are very much localized.
Of course, that's assuming that she's Japanese - it's going to be a lot harder for her to get any service if she's not, because she'll need a gaijin card and all.
Actually, you just made me think of something.
If she's Japanese, and her family has broadband internet like Yahoo or NTTs own service, then a lot of places allow you to log in with your account credentials. You can sign in with your BB account at most (if not all) McDonald's for free, and many large train stations have cafes where you can sign on with your NTT credentials.
Otherwise, most (if not all) Seattle's Best Coffee stores in Japan offer free wireless internet connections.
If you need to rent a mobile wifi hotspot for a vacation, then you might want to check out http://www.rentafonejapan.com/. I used them for cell phone rental on my last vacation and it worked out quite well. The cell phones are on Softbank, and the hot spots are on Docomo.
They have a decent delivery and return policy. If you are staying at a major hotel, they can ship the phone directly to the hotel and when you leave have the hotel return it for you. Since I was renting an apartment (which included a wi-fi hot spot), I opted to pick up and return at the post office in the Narita airport.
The prices were pretty reasonable, and having a mobile hot spot was very useful when using Google maps to navigate. I will say that the Wimax coverage did drop out in some areas--particularly between train stations underground. There was connectivity in most areas we went to in Tokyo, and you could re-establish connection at each terminal.
Also something to keep in mind. Sometimes the hot spots can get stuck in a funky state and it either won't emit the wireless signal, or be able to connect to the cell towers when it could just a little bit ago. The solution is to simply turn the thing all the way off and then back on again. That seemed to work the 3-4 times I needed to try it over my 2 week vacation.
That's quite true. 3 months ago, I came to Japan for short-term study for Japanese language in the international school. I rented the mobile wifi hotspot and quite convenient. The speed is not much different from cable internet and I can share with my roommates. In the beginning, I rented for per day, but I found it's not bargain. Then my classmate told me that I can rent iVideo WiFi on website. Fortunately, they are promoting and I rented only 2800 yen for first month. Now the wifi is beside me, it looks quite colorful. If needed, check the link http://goo.gl/MMCfXD