- Oh Search PR0 http://www.ohsearch.org/
- Oklahoma Online PR3 http://www.oklahoma-online.com/
- Online Directory World PR0 http://www.onlinedirectoryworld.com/
- Open Directorys PR0 http://www.opendirectorys.com/
- OSWD PR0 http://www.oswd.us/
- Oz Names PR2 http://www.oznames.com/