If you're thinking of only having an iPhone and not also an iPod you might want to consider how battery life is going to affect you. A busy day on my phone can drain the battery pretty quickly. Add using the iPhone for music and it's only going to drain faster. I have a 32G iPhone, but I only use it for music as a back-up to my iPod. Unless you have easy access to chargers throughout the day, you may want to consider keeping both.