I jokingly refer to my iPhone as my 'auxiliary brain'. If I didn't have it, I would have to get something like it. It is used for reminding me about important things to do, calander/ diary, providing just-in-time access to documents via Dropbox, as my presenting tool (using wireless) and communication when I am away from the office.
However, this range of use is not universal for all users. For example, how many of us use the full power of MS Word? When we need something done, we learn how to do it or ask someone. If we don't perceive we need it then we don't spend time even exploring.
In the use of educational technologies, the usability, context and purpose are key factors to adoption. For example, in my current project with iPhones, if a student doesn't perceive a suitable use for their iPhones, they generally do not bother to explore, even when we as the researchers suggest that something might be useful for improving their organisation (diary) or learning (podcasts of grammar from GrammerGirl - see http://grammar.quickanddirtytips.com/). Familiarity and existing ways of working are key inhibitors to changing practice and should not be underestimated in any study purportedly intent on changing learning behaviours.