toddos, there's a big difference between the size of a smartphone screen and a tablet which is what outlander78 was saying... holding a smartphone to your ear is not holding an iPad to your ear...
Owning a smartphone is not an either/or situation either... but until my smartphone has a flexible eInk screen that will expand to 6 inches and has a 7-15 day battery life then the reading gets done on my eReader (which I have no trouble taking everywhere) and everything else gets done on my smartphone, everything but reading...