Put a Header with Graphics on Every Page in Drupal

It really depends on the effect you're going for. If you're talking about a large rotating image area then views slideshow rotator module provides you with a block that you can then insert.
e.g. http://demo.symphonythemes.com/index.php?theme=shamisen

Do you have an example of what you're going for?

In reponse to both of you, I want to put a drop-down menu on every page like this:  www.serve.gov