And here's something that isn't a hoax, but is rather curious. If you type the mysterious numbers from Lost (4 8 15 16 23 42) into google maps, they correspond to the approximate latitude and longitude of an island in the middle of the Pacific. My guess is that this probably isn't an accident.
Update: A few more hoax websites of Lost:
http://www.driveshaftband.com (the website of Charlie's band. Thanks to Nordan for this link.)
http://www.mrcluck.com or http://www.mrclucks.com (websites of the fast-food restaurant that Hurley used to work in, before he won the lottery. As far as hoax websites go, these aren't very fully developed. The front page simply links to a podcast about the show.)
The island in the Pacific mentioned above is Kosrae Island (Thanks to Eric Schucard and Tim for this info).