ICT Facts and Figures has a link to a short document which contains, amongst other things, statistics relating to the number of mobile (cell) phone subscriptions and mobile broadband subscriptions.
Appy to help gives some ideas and research statistics on the potential of using mobile phones in the classroom.
Hartnell-Young and Heym (2008) - Based on study in 2007-8 involving five secondary schools in which a subset of teachers worked with specific pupils/groups of pupils using mobile phones (smartphones) for periods ranging from one day to nine months. Resulted in a set of eight recommendations for schools about how to move gradually from a total ban on mobile phones to 'normalised' use.
Using mobile phones in education
Discussion about banning mobile phones in classrooms (in England) on the Learning Without Frontiers website
40 creative ways teachers are using mobile phones in the classroom, which you can access at www.onlineuniversities.com/blog/2012/10/40-creative-ways-teachers-are-using-cell-phones-classroom/ (we were asked to remove the live link so you will have to cut and paste the URL)
Heppell & Chapman (2011) - Report on a project that aimed to help bridge the divide between schools that were engaging with mobile technologies and social networking and those that were 'locking and blocking'. The report is based on accounts of what is working in some schools, from the teachers involved. Areas addressed in the report include: mobile phones, Facebook, Twitter, and YouTube.