I used to be a big fan of RAID5, but lately, and for certain circumstances, especially home servers, I've become more of a fan of mirroring.  Here's why.

1. Both instances of major data corruptions I've had in the last 10 years or so have been caused by my CERC RAID (Dell re-branded Megaraid EIDE) controller!
2. If/when that controller dies, the RAID is useless and the data inaccessible.  With a software mirror, a) there is no controller and b) either disk Just Works stand-alone.
3. The 1u servers I've been using lately have room for 2 disks (minimum for a mirror) but not 3 disks (minimum for RAID5).
4. Software mirroring is cheaper in that you don't need a controller.  It's arguably more expensive since you lose half your disk space instead of N-1 as in RAID5, but with disks so large and cheap these days, the added flexibility and reduced complexity of a mirror is more than worth it.
5. It's possible to "clone" a system by yanking one of the mirrored disks and installing it elsewhere, then adding new blank drives to both systems and allowing the mirror to rebuild.
6. If you move software mirrored disks into a new server they should Just Work.  The same is true when using n external controller (until it dies), but that's not the case if using a motherboard-based controller, so watch out for that.  When the MB dies you can lose the board and your data.
7. Fewer drives cause less heat and power consumption.
8. Software mirroring is faster on writes than software RAID5, and possibly even hardware RAID5, depending on the controller, since RAID requires doing some math while mirroring is just sending the same plain or write to two places.

Now, having said all of that I don't think RAID5 is bad or inappropriate or anything.  I'm just saying that a software mirror is a really handy thing to use, especially at home.  I've also completely ignored RAID10, 01, 6, etc.  Those are all great for heavy duty production environments, but for home use these days I don't think you can beat a software mirror on Linux + LVM.

Also note that any/all RAID, including mirroring, simply provides disk failure tolerance.  It is not a substitute for proper and tested backups!  I like BackupPC but there's a lot of great backup software out there. See also: http://www.backupcentral.com/.