Of all the viral marketing campaigns I've seen over the last few years, I've really been digging how Fringe is carrying-over one of the running mysteries of the show into the real world: namely, the appearance of "The Observer," a creepy-looking bald man in a black suit and fedora, who has shown up (on camera, of course) at real-world events ranging from NASCAR races to NFL Football games.

With this week's episode of Fringe, entitled "August" we learn more about the The Observer - namely [SEMI-SPOILER] that "The Observer" is actually "The Observer(s)," with a hint as to what the purpose and/or agenda of these mysterious beings means for the world(s) of Fringe. To help promote the episode, Fox has been sending "Observers" out into the real-world, to be spotted by those keeping a careful eye on everything related to the show.

As of recently there have been Observer sightings in and around NYC, LA, Chicago, Boston and Atlanta. The dedicated folks over at The Observer Trackers on Facebook have been keeping a nationwide thread open and updated, announcing and then logging the places where fans can run to be a part of this amusing game of hide-and-go-observe.

Here are some recent photos taken  of Observers making their way through "our world":

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Atlanta

Los Angeles

For those of you who fancy yourselves historical experts, The Observers have been here longer than you might think...

fringe Observer Historical

(Hint: Left side)

Finally, here is a televised Observer sighting, captured during this week's episodes of Fox's So You Think You Can Dance:

For a more extensive gallery of Observer pics, head over to The Observer Trackers on Facebook.

Viral Marketing can be really (really, really) annoying, but little "games" like this are pretty harmless and are, in general, a real thrill for fans. The lengths to which Fox has gone with this Observer campaign have been unprecedented - I remember during the Fringe panel at the 2009 New York Comic Con when the show's  producer, Jeff Pinkner, told us how Fox had even lobbied (hard) to have an Observer on the platform standing next to President Obama on Inauguration Day. Needless to say they were unsuccessful (or were they?).

Gotta wonder if this latest mass Observer invasion is in any way an attempt to boost the show's recent ratings slump...

Fringe airs on Fox Thursdays @ 9pm.

Sources: The Observer Trackers on Facebook via Sci-Fi Wire