I came across this article online.
 
writersdigest.com/article/directory-of-self-publishing-companies/
 
It's dated January 2009, but I believe most if not all of the information is still accurate and most definelty relavent. It lists over 60 self-publishing companies. Although only a small portion of these companies are listed directly on our site, further research will be conducted over the summer months to expand our listing of print-on-demand vendors. Do any of the users here have any experience with these companies? We'd love to hear from you!