There are a variety of Linux software RAID-like options out there which each have their own quirks and features. Personally, I like the simplicity and functionality of mdadm. It provides redundancy with a minimum of cost and hassle, assuming you do everything right.
The important piece of that is doing everything right. One critical piece of information that is not often discussed is that software RAID should always be built on top of partitions, not with raw disk devices. The reason for this is that superblocks get written to the last raw disk in the RAID volume instead of the software RAID partition. At boot the kernel will read the partition table from the raw disk for the RAID volume and cause all kinds of nastiness. The partition tables will all look wrong, the kernel will write to addresses on the disk that don’t exist, and you will generally be unhappy with your system. So plan ahead, create those partitions first, and then create the SW RAID volume using those partitions and lay your fs on top.
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While the advice above is still sound, since mdadm 2.6 it has been possible to create a “partionable” RAID1 volume for booting purposes using whole disks. See http://wiki.centos.org/HowTos/Install_On_Partitionable_RAID1 for details.