Like most countries, the keitai (mobile phone) has become a huge part of life in Japan, and for the younger generation, cell phones seem to be supplanting the personal computer as the primary Internet device of choice.

The newest trend is young people using their phones to access sites called purofu ( “prof,” from the English word profile, which looks very similar to “blog” when rendered in katakana), centralized services that allow people to create profiles for themselves showing their pictures, specifying their age and location, and listing their favorite music, movies or food.

These purofu services are sort of like guestbooks optimized to display on cell phones, where people can search for keywords then leave comments or links and have random, meandering discussions, creating a way for lonely Japanese young people to make friends.

No one knows exactly how many users of these services there are in Japan, but conservative estimates start at 1 million or more.

The new Internet services aren’t without problems, however, some of which came to light last week when a 17-year-old student attacked a 14-year-old in Chiba Prefecture with a metal baseball bat for writing insults on his profile page.