Penn and Teller did an episode of their Showtime program Bullshit on circumcision and part of the episode focused on restoring the foreskin. It involved taping weights to yourself and stretching it out (I’ll pass on that, thanks).
As a side note, I highly recommend watching Bullshit (especially the folks here), as it deals with debunking myths/hoaxes and exposing frauds; it does so in a humorous manner, too. Be forewarned, the more you don’t see eye to eye with Penn and Teller on whatever subject they are covering, the higher the probability you won’t like the show. They are very opinionated and you’re likely to be refered to as an “insert negative adjective” fuck many times throughout show. I rarely find myself on the opposing viewpoint of their subjects - most of the time I just disagree with one or two points they try to make while validating their view.