In a question left at the MacCast Feedback site, http://mcfeedback.blogspot.com listener Shayne wanted to know about backing up OS X. There are several options available depending on what level of backup you want.
1) If you have a .Mac account you can get Backup2 from Apple for free. It allows you to backup to disk or removable drives and can be scheduled.
2) SilverKeeper is a free backup utility from LaCie and does basic incremental syncing of files and can be scheduled.
3) Dantz Retrospect Desktop is a commercial app ($99.00 USD) that should meet most backup needs.
4) Carbon Copy Cloner is a utility that will create a complete bootable backup image of your entire drive. It also offer syncronization and scheduling of backups. It is also free.
Another MacCast listener, Paul, recommeneds using the UNIX command line utility rsync. He even provided this link to an article he wrote on the topic.