No, definitely not. Smart phone technology has many more bugs and limitations than any standard computer, plus it's still in its growing stages. More than that, when it is used as a phone, music player, web browser and with its multiple interfaces (bluetooth, wifi, data hotspot, cellular signal), the potential for information theft is very high.
It's definitely going to happen though, and eventually will be integrated into our bodies as an implant. We've moved from actual gold and silver to promisary notes to plastic numbers where money's worth is transferred electronically, so moving to mobile phones and then implants is a natural next step.
I would be much happier if we used actual metals that were worth their weight. Now the value of a dollar decreases constantly. Just think of the control that can be exercised over your value when even promisary notes are abolished.