I had a couple drives that used to be part of a Linux RAID setup. The easiest way I've found to grab the data off them is TestDisk - it's a handy tool that will copy files off a drive that was part of a RAID array. Even better, you can run it from Linux and Windows. In my case, my new main machine is a Vista box, so I don't have to figure out how to get my VMware instance of Ubuntu to read drive image files on the Windows box.
I found TestDisk through this article: Mounting Linux drive images