Earlier this year, the web site for the Bush-Cheney campaign - the real one, paid for by MBNA America and Richard Scaife - featured a "create your own banner" tool, where you could enter your own slogan and print out your own poster, with the Bush-Cheney logo, and a note at the bottom "paid for by Bush-Cheney '04, Inc." Democrats, of course, couldn't get enough of this.
The original sloganator accepted everything, then it started censoring profanity and words like "Hitler," "dictator," and "evil." Nevertheless, many clever folks exploited the sloganator to their own ends before its sad demise only a couple of weeks after its birth, and its mourners assembled some of the best for the slide show.
http://homepages.nyu.edu/~meo232/sloganator/