Ah ha....in case anyone is reading this and wants to know, the directions RefreshGFX (and Dynamoash) posted totally explains: [WordPress › Support » [Plugin: Contact Form 7] custom submit button](http://wordpress.org/support/topic/plugin-contact-form-7-custom-submit-button?replies=9).
A couple of things that may be helpful:
If you don't want to use FTP, to get to the style sheet, go to Plugins > Contact Form 7 > Edit > contact-form-7/styles.css from the list of files on the right (as of June 2011 this it is styles.css not stylesheet.css as Refresh stated).
Does anyone know how to remove the "Submit" text? I wanted to use a button that already had the text on it. Thank you!