Xfactor design  
   Offers logo, print, website, interactive, display and outdoor design. Also provides marketing. Includes portfolio. Located in Houston, Texas. [Requires Flash]
   http://www.xfactordesign.com/

XK3 Graphic Services  
   Print media, web design, photography, and illustration, including book cover design and logos. Hendersonville, Tennessee.
   http://www.xk3.com/

Xerxes Studio  
   Specializes in document, advertising, and logo planning and design, corporate identities, packaging, and website planning. Online portfolio. Los Angeles, California. [Requires Flash]
   http://www.xerxesstudio.com/

Xeno Design  
   Design, advertising, promotion and web site creation. Chicago, Illinois.
   http://www.xenodesign.com/

XMi Ltd.  
   Dublin, Ireland based print and web design firm specialising in corporate identity and literature, product branding, advertising, web, and multimedia development. Portfolio, company background, and senior staff bios.
   http://xmi.ie/