PR 3 Sites

Art PR3
http://www.designfirms.org/linkexchange/arts/web-design/
http://www.designfirms.org/linkexchange/arts/education/
http://www.designfirms.org/linkexchange/arts/crafts/

Business PR3
http://www.designfirms.org/linkexchange/business/automotive/
http://www.designfirms.org/linkexchange/business/chemicals/
http://www.designfirms.org/linkexchange/business/directories/

Computer PR3
http://www.designfirms.org/linkexchange/computers/computer-science/
http://www.designfirms.org/linkexchange/computers/operating-systems/

Health PR3
http://www.designfirms.org/linkexchange/health/environmental-health/
http://www.designfirms.org/linkexchange/health/products-and-shopping/
http://www.designfirms.org/linkexchange/health/senses/

Shopping PR3
http://www.designfirms.org/linkexchange/shopping/antiques-and-collectibles/
http://www.designfirms.org/linkexchange/shopping/music/

Other PR6
https://www.socialtext.net/wikinomics/index.cgi