HomeSteps - Freddie Mac 
A purchaser of mortgages on the secondary market with an database of properties available nationwide.
http://www.homesteps.com/GreenPoint Financial 
Detailed listing of bank owned properties with photographs and contact information.
http://www.greenpoint.com/
Premiere Asset Services 
Nationwide servicer of bank owned properties. Offers online search and property photographs.
http://www.premierereo.com/
Integrated Asset Services 
Offers nationwide listings of bank-owned and reo properties for sale.
http://www.iasreo.com/