A simple thank-you note after a job interview could help you get an offer. If you've got a CV with page after page of lengthy job descriptions, you'll need to do some revising. That just doesn't cut it with a U.S.-style resume.
Brevity is key.
U.S.-style resumes typically run one to two pages in length, rather than the five pages, or longer, common for CVs. The resume should telegraph its information, rather than offer in-depth detail. Keep that image of a time-crunched personnel manager in your head. You want to attract his attention, but you don't want to put him to sleep. It shouldn't be.