If you don't have a bag, pocket, or anywhere to stow that iPhone, how about kicking it around on your heels?
The shoe was designed around iPhone cases from 3D-printed accessories site FreshFiber. You can see the cases in the base of the heel.
While it was exhibited last year at Milan Design Week and Maison et Objet Paris, Nguyen recently showed off his creation in London, where he attended the launch of Print Shift, an on-demand magazine devoted to 3D printing.
"We relate a lot to DJs," he told BBC News. "Because they take other people's things and they put it together to create something totally new."
Nguyen said the iPhone Mashup Shoe is designed for a size 37, which is about size 6 in the U.S.
"They actually work. I heard they're pretty comfortable but I haven't tried them myself."
Check out Freedom of Creation's imaginative 3D products, ranging from jewelry to lighting to furniture, here.