Get a book on writing business/cover letters. Brainstorm and research the company then write a creative, individualized cover letter showing that you know about the company, you know what they want, and by God, you are IT.
Some companies will ditch it immediately, but the ones that read CLs will be impressed. I've had calls for interviews in the past from Chief Pilots who asked me to go over my resume over the phone because they only have the cover letter with them.
It takes a little effort and work, but it pays off to be the one who catches their eye.
Good Luck!