Wapreview has the most interesting article published on mobile in Japan:
3G seems to be taking Japan by storm. In wandering around the city, I saw many of the latest 3G handsets in use. One of the most popular seemed to be NEC's Linux based N902i on the DoCoMo FOMA network. The nicest part for me was the Netfront browser on the 2.5 inch, 240 x 345 (dubbed QVGA+TM) TFT screen with 262,144 colors. Many Japanese feature phones run either Linux or a version of Symbian with a Japanese developed UI called MOAP ("Mobile Oriented Applications Platform").
It is a common observation that the Japanese use their phones constantly but rarely speak on them. I can certainly vouch for that. On the subway, where signs warn that phones must be silent - about half the riders at every given time were tapping away on their phones. Surreptitiously looking over the shoulders of my fellow riders, I did an un-scientific survey of what they were using their phones for. About 50% seemed to be browsing the mobile web, about 25% were reading and responding to e-mail and the remaining 25% playing games.
While they are not new, having been in use in Japan for at least a couple of years, QR Codes. QR codes are very versatile. Scanning a QR code with a QR capable phone can add contact information (typically from a QR Code on a business card) to the phone's address book or launch the browser and load a mobile site or load a ring tone or an image containing a map to a store. When we visited Kamakura, home of the great Buddha and other shrines and temples, the tourist information counter at the train station was giving out a map in English and on the map were QR codes for the Kamakura town i-Mode site as well as at least a dozen other QRs pointing to the mobile sites of advertisers.
Tags: mobile, software, smartphone, emerging