Each week in this column, we'll take a look at some form of entertainment and its Web-based PR efforts. We'll dissect the success of everything from Web-based mysteries, a la Lost, to creative ways authors are promoting books, to Web sites created just because a character in a movie or TV show uttered the phrase "___.com."

Apatow Productions is hoping moviegoers aren't Forgetting Sarah Marshall after the film's opening weekend, April 18, and are using various Web sites to encourage fans to keep buzzing about the comedy, which stars Jason Segel and Kristen Bell. In the film, Bell plays Sarah Marshall, an actress on the TV show Crime Scene: Scene of the Crime, and her boyfriend Aldous Snow, fronts a band called Infant Sorrow. Both the TV show and the band have their own Web sites — NBC hosts Crime Scene's while Infant Sorrow's can be found on MySpace — complete with two tracks performed by the band. The character Matt the Waiter, played by Superbad's Jonah Hill, also has a MySpace page, showcasing his life goal of being a rock star and his love for Infant Sorrow.

These sites, which bring fictional parts of the movie into real life, are in addition to the official ForgettingSarahMarshall.com Web site, fan site SarahMarshallFan.com, and www.ihatesarahmarshall.com, which was created as Segel's character's personal blog.

The Web sites for Crime Scene and Infant Sorrow are modeled after real TV shows and bands, and include photo galleries, clips from the TV show, songs by the band, and message boards. These sites try to give fans a way to incorporate the movie into their lives that goes beyond going to see the flick at a theater, or waiting for the DVD. The sites also aim to create buzz, especially given the target demographic for this film, the same crowd that packed theaters for Apatow Productions' previous successes: 40-Year-Old Virgin and Knocked Up. 

Also hot online:

The second Robin Sparkles video, from CBS' How I Met Your Mother, has been posted on MySpace.

Madonna's upcoming album, Hard Candy, has been leaked online. It wasn't scheduled to be released until April 29.

Björk fans can watch the singer's latest video online in 3-D.