Thanks for the lead prima, more on parody use from:
http://cyber.law.harvard.edu/metaschool/fisher/domain/tm.htm
Finally, certain parodies of trademarks may be permissible if they are not too directly tied to commercial use. The basic idea here is that artistic and editorial parodies of trademarks serve a valuable critical function, and that this critical function is entitled to some degree of First Amendment protection. The courts have adopted different ways of incorporating such First Amendment interests into the analysis. For example, some courts have applied the general "likelihood of confusion" analysis, using the First Amendment as a factor in the analysis. Other courts have expressly balanced First Amendment considerations against the degree of likely confusion. Still other courts have held that the First Amendment effectively trumps trademark law, under certain circumstances. In general, however, the courts appear to be more sympathetic to the extent that parodies are less commercial, and less sympathetic to the extent that parodies involve commercial use of the mark.
So, for example, a risqué parody of an L.L. Bean magazine advertisement was found not to constitute infringement. L.L. Bean, Inc. v. Drake Publishers, Inc., 811 F.2d 26, 28 (1st Cir. 1987). Similarly, the use of a pig-like character named "Spa'am" in a Muppet movie was found not to violate Hormel's rights in the trademark "Spam." Hormel Foods Corp. v. Jim Henson Prods., 73 F.3d 497 (2d Cir. 1996). On the other hand, "Gucchie Goo" diaper bags were found not to be protected under the parody defenseGucci Shops, Inc. v. R.H. Macy & Co., 446 F. Supp. 838 (S.D.N.Y. 1977). Similarly, posters bearing the logo "Enjoy Cocaine" were found to violate the rights of Coca-Cola in the slogan "Enjoy Coca-ColaCoca-Cola Co. v. Gemini Rising, Inc., 346 F. Supp. 1183 (E.D.N.Y. 1972). Thus, although the courts recognize a parody defense, the precise contours of such a defense are difficult to outline with any precision.
Another great site on the subject:
http://www.patentfla.com/articles/trademark_parody.htm
primacomputer said:
Your best defence would probably be on the grounds of parody. You are given much more leeway here. After all, if your parody is so dissimilar to what you are trying to parody then no one will “get it”.