I'd post again in one of the CNET MacOSX forums.
Here's a link -> http://forums.cnet.com/mac-forums/mac-os-x-forum/?tag=contentMain;contentBody
I tried to convert two 80 Gig external hard drives into a 160 Gig hard drive using Disk Utility's RAID function. Surprise, I can only store 73 Gig on the RAID. That's of no value.

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