Popatopolis is about director Jim Wynorsky's quest to make The Witches of Breastwick in three days. He's the guy who gave us Chopping Mall (starring Barbra Crampton, my all-time favorite scream queen) and the sequel to Wes Craven's Swamp Thing. It's a pretty pleasant documentary with a few laughs and a lot of breasts. Unfortunately it would have been better had it been about his older movies rather than his recent foray into softcore pornography.
If you're not a seasoned B-movie nut, I'd suggest starting with Corman's World. The rest of you though should probably check out Popatopolis. Wynorsky turns out to be an angry but oddly likable guy. Too bad the B-movie is dead these days.
Bonus video: Barbara Crampton and other scream queens at a horror convention in Atlanta. Amelia Kinkade of Night of the Demons fame appears here, too; you may also remember her going full retard as The Pet Psychic (I shit you not).