I came across a link to this on
Whedonesque and was absolutely charmed.

I've seen many other versions of this bumper sticker, usually based on religious symbols.
In this case, the C is formed by the Death Star, eclipsed to make it look like a crescent. The Enterprise, seen from above, forms the O and the E. X is an X-wing fighter, again from Star Wars.
The Doctor's sonic screwdriver is the letter I, and then we have the swooshy S from Farscape credits and Serenity, my favorite space ship, as the T.
What I love about this version (besides the fact that the artwork itself is beautiful) is how much it says about fandom, and SF fandom in particular.
Because fandom is so very much like religion. All our squabbling sects, large and small. We get passionate about them. We evangelize. We hurl anathemas at one other. But we
can get along, if we want to badly enough.
And look how well this image reflects SF fandom itself. The first four letters in COEXIST are drawn from two of the oldest and largest camps: Star Wars and Star Trek. Then there is the smaller, but still well-recognized Doctor Who. And off to the side, the fringe cults of Farscape and Firefly, whose adherents' fervor is fed by the martyrdom of cancellations. Hee!
I'd love to see this done with a greater variety of sources for the letters. What a beautiful picture of our multiverse.
ETA: Son says that the dot above the I is a Stargate. I had seen it as the glow from the Doctor's sonic screwdriver, but now that he has pointed it out I see he's right. Also, Son says that is
not an X-wing from Star Wars. He doesn't know exactly which show the x-shaped ship is from, but Son knows his
theology canon, so I'll take his word for it.