I don't have a cell phone and never have in my entire life, but I have been glued to computers for the majority of it. So, I can't really say a lot on the topic, but I do think it depends on the person posting more than the deice they're using as to how long their post would be. Not to mention how much they have to say and how far they're willing to elaborate their point. I find I end up elaborating a lot but that's because I can't convey what's on my mind in person to people very easily, so online communication for me is a way to bypass my social ineptitude. Maybe I compensate with a vocabulary I've accumulated over the years because I do so poorly in interactive or in person conversations, but I don't really know. In the end though, I really do think if people want to make a post long enough then they will regardless of the device they use to do it. These are busy days though for most people, too, and not a lot of people have a lot of free time to type that much. At least that's my take on the subject.