The automated services listed in this post will create your banner for free. Just fill in a form and the banner is constructed for you as an image you can download.
http://www.freenetcodes.com/mybannermaker_myspace
Free online banner maker with many configuration options, such as: change font, select banner size, background, text color and upload your own background image.
http://www.gifworks.com
free online tools to make animated GIF images, including banners. Highly recommended.
http://nis-ei.eng.hokudai.ac.jp/~yamamoto/factory
Free instant automated service: 2-line banner, 3-D banner, instant 3D font maker, brass-like name plate.
http://quickbanner.com
Online instant free and non-free banner creation tools (animated, flash, button, GIF, etc).
Free Banners Exchange Services
A 'banner exchange service' enables you to advertise your Web site on other Web sites for free. More specifically, in exchange for placing a banner on your Web site, your banner will be displayed on other Websites for free. A banner is usually a GIF or a JPEG image avertisement.
http://www.free-banners.com
Exhange your banner with over 150,000 other members sites.