When you think of '50s musicals, the first term that comes to mind probably isn't the Internet, but Singin' in the Rain maintains a respectable, albeit small, fan following on the web. There's an official Facebook page, for example, featuring regular updates. YouTube is filled with fan videos recreating and remixing the titular tune. Those talented kids from Glee even got in on the act and mashed "Singin' in the Rain" up with Rihanna's "Umbrella" (and threw Gwyneth Paltrow in for good measure).
Most of the Internet's love for Singin' in the Rain gets channeled directly through star Gene Kelly, though. In fact, Kelli Marshall, a lecturer of Media Studies and Cinema at DePaul University, is arguably the biggest Kelly authority on the web. She's taught a class on his films, runs a popular fan site aptly titled Gene Kelly Fans, and has even taken an in-depth look at what Gene Kelly tattoos say about modern fandom.
Fans who don't want Don Lockwood's face permanently inked on their bicep can settle for following @GeneKellyFans on Twitter.