Add a postscript, especially one that's handwritten, to your cover letter -- just make sure it relates to your USP.

P.S. My distinctive background has well equipped me with the tools to be an asset to Bain and Company.

P.S. My fluency in several Slavic languages is just what Darwin needs as the firm opens new overseas markets.

P.S. I have a solid grasp of HTML, Java and other Web development software would enable me to develop Web sites to market your company's services.