Sooo, Travelocity's guerilla marketing campaign ripped straight from the movie Amelie seems to be working out well for them.
On messageboards and various forums people keep asking who stole my gnome? and linking to whereismygnome.com, ever since the campaign started December 9th. Missing gnome posters have been posted all over US cities (.pdf here) and there's even a a toll-free number to call if you've seen the gnome. If all that hasn't tipped you off that it is indeed a viral, well, then just watch the fake news report (QT and Windows Media).
Ads imitate art again, and again, and again... Gnomes are so 1999. ;)