Parodies, once a cheaply filmed niche segment of the adult movie market, are big business these days - filled with expensive special effects, real story lines, actors who can (sometimes) actually act and costumes that even comic-book geeks find authentic. The movies may also help save an industry looking to rebound from years of Internet piracy, illegal downloads and amateur videos that have caused a serious financial hit, said Mark Kernes, senior editor at Adult Video News. The business has gone from annual revenues of as much as $12 billion a few years ago to about $7 billion today