I'm with Jeremy. I've got a cheap (and now very old) PAYG phone that works, as well as a camera and PDA, etc. each chosen to do what it's supposed to do. I can upgrade any of them as and when required, which I frequently do with cameras. I don't want them all in one package, however smart. I'm not likely to get mugged for my phone, either...
Tools for the job
I'm with Jeremy. I've got a cheap (and now very old) PAYG phone that works, as well as a camera and PDA, etc. each chosen to do what it's supposed to do. I can upgrade any of them as and when required, which I frequently do with cameras. I don't want them all in one package, however smart. I'm not likely to get mugged for my phone, either...