A recent Washington Post article, distributed on the telecom-cities mailing list, reports on a number of interesting aspects of mobile phone use in Japan that we don't see here in the USA. Among the highlights:
The article reports that "Restaurants advertise immediate discounts on Web sites when they have a slow night, offering price cuts of as much as 15 percent to fill seats with keitai bargain hunters." It does not, however, say whether the recipients of such advertisements find them intrusive or welcome. I'm somewhat dubious about the claim that "Japanese have grown so skilled at writing e-mails on cell phones that many now find it simpler than using computer keyboards."
After reading the article, a quick google of "keitai" (Japanese word for mobile phone) reveals that much of this, and more (including pictures), is extremely well-documented in a November post on Chris Heathcote's fabulous blog (I must really visit there more often).