If you have a local business and want to Add, Change or Remove your Business Listing, Yahoo has a new website: listing.local.yahoo.com
We changed our listing at no-charge. It is similar to the process at Google Local and Bing Local. You can verify your business listing by email, phone or post card. The Yahoo Small Business Center has a URL that uses this interface.
This process took about 30 days to change. There is a contact form to customer support if you want to remove a listing.