Foreskin restoration stretching.

There are several companies out there selling devices to restore, through stretching, circumcised men's foreskins. It has been well established that stretching of skin tissue promotes mitosis and can actually cause skin to regenerate. Based on this, foreskin stretching, in combination with topical steroids, is often prescribed to treat phimosis. Research has shown this type of treatment to be very effective.

These stretching devices take the concept one step further, the idea being that a foreskin can be recreated through stretching of the remaining skin (i.e., the skin left behind after circumcision). Whether or not these stretching devices actually work to restore foreskins (as opposed to treating phimosis) isn't clear - I couldn't find any research.

The Dual Tension Restore (pictured above) is one of the devices being marketed for foreskin restoration. The homepage for the device, with lots of photos of it in action (NSFW!), can be found here.