You can now get digital out from an iphone5 using Apple's Lightning to USB adaptor under IOS7. The iphone will not power a USB-powered DAC. If you do get a USB powered DAC, you will need to put a powered USB hub between the iphone and the USB DAC. Check out threads on computeraudiophile.com. If you are looking for a portable product, there are more coming out every day (self powered is better, as the iphone will only provide a tiny bit of power). I have a JDS Labs C5D portable DAC/headphone amp. I think there are more portable options right now with the Galaxy phones, but there definitely are options for iphones and more coming.