For the smaller databases, we backup a flat file dump of the Oracle database that our DBA crea tes each day.  For the larger databases, we utilize the Oracle backup agent and take hot backups.  The first method is certainly easier, but when the db's start to grow and get very large, it can be a cumbersome way to get a backup of an Oracle db.

The dba's wrote a script that backs up the database to a disk file on the same server using the RMAN stuff - to a file system called backup.

Once they got the script working correctly I then went in a added to the script.
Checking to see that the backup to disk finished ok - if it failed - email the dba's that backup to disk failed.
If it worked - then I put in the netbackup command to do a user backup to tape of that backup dir.
(this means a user schedule in the policy)
Again I check that the backup to tape went ok - if it failed - email my group that the backup to tape failed.
If it worked - email both groups that the backup was successful.

What I like about this is -
1) I don't have to know anything about RMAN or how to get it working with netbackup
2) the dba's can be in control of the backups (some what).  as the script is run via a crontab entry in oracles crontab file - the dbas can set the time they want it to run - and if they are doing work on the server ( say a change control) and do not want the backup to start yet, they can comment out the cron entry.   When they get done they can just 'at' the backup script to start.
3) if a restore is required - or a refresh of the test and stage enviroment need to be made from the production backup - they can just nfs mount that backup dir to the test server and do a restore - no need to get me involved.

Because the script does both the RMAN and the Netbackup, - this means the Netbackup part will not start until the RMAN part is done. 
No more having to check your timing to make sure you don't start the tape backup before the backup to disk is done.

I sent the script to your forum mailbox.
 

The RMAN sounds like what our DBAs are doing with our test and staging DBs.  We use Tivoli Workload Scheduler, so the scheduling software kicks off the scripts and backups.  The DBAs wrote verify scripts comparing the backup using bplist vs what is in the oracle db directory and it emails them and the backup admins when finished.

We have not tried the Orqacle Backup agent.  Since having a dedicated scheduler, for the DBs that need to be in hot backup mode, the schedule does it, then the backup starts.  After it is done the schedule returens the DB to normal mode.

So it sounds as though we are doing it close to what you guys are.

Thanks for the replies, I would like to see some more answers.  Like using the RMAN agent of NetBackup, ease of use, recovery.  Is it worth it?