Disaster Recovery for Oracle DB

Dear All,
Is there any white paper or case studies, or various Disaster Recovery implentations for Oracle Databases. I am planning to do a DR for Oracle Databases which are running 24 * 7. There are no downtime at all. Found some documents from Otn.oracle.com, explaining about the Backup & Recovery, Standby concept, Datagaurd in 9i, replication etc., If any one can help me in finding out the situation based DR implementation?