A mysterious postcard pointed me towards the outwardly unassuming website of a small New England town, where I am invited to become an honorary citizen "by being dunked in the Miskatonic River." Wait, what?
With the back of the postcard reading "Dark Days are Coming," there can be no doubt that this is a viral website for Funcom's upcoming real-world MMO, The Secret World, and it's nice to see the team having so much fun with the subject matter. The Secret World is a game in which all of the strange myths, conspiracies, and dark things you see out of the corner of your eye are real, so it makes perfect sense that H.P. Lovecraft's Cthulhu Mythos would be making an appearance.
Kingsmouth is likely modeled after Kingsport, a fictional Massachusetts town in which Lovecraft based several Cthulu stories. They seem to have moved things to Maine, but all in all it fits.
Update: Several commenters have pointed out that it actually works better as a combination of Kingsport and Innsmouth, another favored fictional Lovecraft location.
I wouldn't want to ruin the fun you'll have exploring the Kingsmouth.com website, so I'll just say that some of the pictures on the gallery page aren't really pictures. Be sure to share your findings in the comment section!