Some I have seen (all available from www.Cafepress.com, among surely many other outlets)  

Middle-Class White Guys for Obama

I Hated Bush Way Before It Was Cool

Latte-Drinking, Prius-Driving Democrat for Obama

Bitch is the New Black (Tina Fey wins the award for closest-to-instantaneous journey from her mouth on SNL to the bumper sticker production line)

Any Democrat '08

Another Bright Blue Dot in a Temporarily Red State

I've seen the following one, but am not sure where it is available:

If You're Not Completely Appalled, Then You Haven't Been Paying Attention
(this one predating the '06 Congressional elections and, alas, every bit as applicable today)

The one I have not yet seen, similar to the immediately previous one, but want to see and put on our car, is:

One Small Blue Dot in a Soon-to-be-Blue State
(this would have a silouette of Virginia, my adopted state, somewhere on the sticker).  
 
I am thinking of trying to peddle production of a modest quantity of the latter or some close version of it to either the Virginia Democratic Party or the Fairfax County (DC burbs) Democratic Party, to see if it catches.  If you like the idea and have a connection to the Supreme Bumpersticker Decisionmaker at either place, please feel free...couldn't hurt if they hear it from more than one person.

Please feel free to share actual bumper stickers you have already seen and like, or ones you would like to see, in this thread.  (or something, anything, really, that you think might help lighten the mood around here!)