SANDISK Phone Drive for iPhone is a great solution to low storage 

Each time we buy a phone, we have to decide which storage tier to go for, and that requires a judgment call – not just about how much storage we need today, but how much we are likely to need for however long we end up keeping the phone. There are times when we’ll get this wrong, but fortunately there’s…

Summary from the 9to5Mac feed. The full story lives on their site.