Ok, I'm going to try this but wanted some more opinions/suggestions.
I've got a Seagate 500Gb HD with Vista Ultimate, etc. I just bought two more of the exact model to create a RAID-5 array. I'm going to try to add the extra drives and create the array without having to start from scratch as far as needing to reload the OS and all my apps/data.
I thought I'd create a RAID-1 from the two new drives, use the Seagate util to move the system from the old (not yet in the array) drive and then once that works, add the old drive into the array and create the RAID-5. Sounds like it might work, right? If not, I've got my data backed up just in case.