External enclosure that supports RAID1?

[M A V I C]

It will connect to a MacBook Pro most of the time. Maybe a G5 on occasion too, but if I has to be MBP only, that's fine.

Thanks for the note on the lower end ones. I found these http://www.cooldrives.com/noname.html

There's this one for $299 and I like that it's compact:
http://www.cooldrives.com/dudralmira01.html
but it's only software - PLEASE NOTE: THIS ITEM USES INITIO 2430L CHIP, THIS IS NOT A HARDWARE RAID SYSTEM. - would you consider this one a "lower end" one?

This one is a hardware RAID1:
http://www.cooldrives.com/dusahddfiusb.html