Sorry this is a bit of a tangent, but Gerardo, I'm a back up nut like yourself ... Got bitten by a nasty HD failure once and now my motto is: "if it's not backed up twice, it's not backed up!"
Anyhow, I invested in a Drobo. I would recommend checking the system out... Especially if you fill hard drives frequently. It does redundant backup in a really interesting way (ie. with proprietary algorithms) that allow me to upgrade a single hard drive bay as needed for more space. You pop out the smallest drive, put in a bigger one and it'll take care of distributing the data in such a way that even if you had a failure you'd be safe and sound.
For me it saved a lot of cash over the long run as I fill up drives quickly working in dual disciplines (music/photo). I only buy what I need at the time and I buy OEM drives. Waaaaay cheaper than buying a crapload of extra GB that I won't need for the next 6 months and upgrading all my drives to match.
Just my two cents
Lem