I have a plain cell phone with Verizon that I seldom use. There are a few occasions when it is essential but my average monthly usage is always very low and often zero minutes. For this I pay Verizon about $23/month and am happy. Verizon also has good coverage in the canyon where I live so I'd like to stay with them. I'm thinking about buying an iPhone for two reasons. One is that the CollectorAssistant people say they shortly will announce that the product is available for the iPhone. The other reason is that I would like to check my email maybe once a day while traveling. I'm trying both to save money and not become obsessed with my smartphone. So I'm wondering whether I can buy an iPhone (maybe just an iPhone 4) and use my existing SIM card (?) and not involve Verizon at all? Also can I then find a free WIFI spot and access the internet via my iPhone for a quick email check?