While doing a little searching, I found some information on email feedback loops for other major ISP’s.

• Yahoo
• Road Runner
• Comcast
• Cox
• USA.net
• AOL (don’t bother, see note 1)
• Rackspace (don’t bother, see note 1)
• Earthlink – Send an email at fblrequest@abuse.earthlink.net and provide your IP range, domains, contact information, and the email address for sending complaints.
• Outblaze – Send an email with a feedback loop request at postmaster@outblaze.com

Interestingly enough, most of them use Return Path for FBL services.

Note 1: AOL and Rackspace’s feedback loop’s are completely useless … as they don’t tell you who’s complaining … just that a complaint is made.   Kind of hard to fix a problem if you don’t know who’s reporting the problem.