Children and mobile technology: the Japanese experience by Masanao Takeyama, in Proceedings of the Children, Mobile Phones and the Internet: the Mobile Internet and Children Conference, 2003. A paper full of compelling insights about how kids use mobile tech and the Internet:

Professor Takeyama described multi-media summer camps (...) in which the children experienced and experimented with new digital media through playing and learning. The children were given mobile technology to try out. The interest was to observe how the kids interacted with the new technology. (...) the children were using GPS, PDAs, digital camera and the Internet and the theme was ‘Exploring Tokyo with wearing digital media’. The kids were given assignments and control centres would receive the information the kids sent in and they would compute a kind of homepage from the uploaded information. The GPS functionality enabled the kids to know where they were and for the organisers to know where the kids were. It was found that the kids were able to learn how to use the new equipment quickly. They didn’t use all functionalities, though the children were able to teach each other. On the Okinawa camp, the children we using i-mode, digital cameras and notebook computers, and the theme was mobile collaboration.

They even performed a 'mobile haiku contest':

The mobile Haiku contest was designed so young people and older people can pair and express themselves by creating Haiku, 17 syllable poems, while walking around town. The same experiment was done throughout the nation. The poems were uploaded, and it was possible to evaluate and score the poems. Any one could participate and act as a judge.

It's a pity, the article is a bit short on how the kids employed the GPS, how they managed to use it and what kind of things emerged from this.