I have a MacBook Air and live with another person who has a MacBook Pro. One of us uses Lion and the other uses Snow Leopard. We will probably add a desktop in a year. I would love to set-up a cheap, user-friendly NAS with RAID1 that we can use for both backups and extra storage. I don't need anything too big and would be happy with a 1TB, but of course more storage is always nice if it's not too expensive. I just learned about NAS a couple weeks ago and all of the NAS options seem really expensive. Any suggestions that I should consider? Thanks!