Two years ago I invested in a Drobo backup disk pack and the Droboshare unit to enable all computers on my network to use the disk. Since then it has been churning away in the background and coping with regular night-time SuperDuper! backups from my various machines. No problems, no hassles, and I've had more peace of mind than ever before. Combined with Dropbox for off-site storage of data, I think I've covered just about any eventuality.
Initially I installed two 1TB Western Digital Caviar Green drives and left two drive bays free for future expansion. Because Drobo mirrors all data so that the failure of any disk will not be fatal, my 2TB gave me about 1TB of effective storage. Recently my data archive had clicked up to 800GB and I decided to add another drive. This time I bought a 2TB Caviar Green from Amazon (at £78, much cheaper than I could get in Tottenham Court Road) and it arrived this morning. I was prepared for a major upgrade session and consulted the Drobo handbook. Surprisingly, the new disk didn't need formatting and all I had to do was slot it into the Drobo without putting the unit on standby or stopping any backups in progress. Couldn't be simpler, and the new disk was sucked in and readied within a few minutes. Now my Drobo dashboard is showing 1.6TB of vacant space instead of the previous 200GB.
By the time I need a fourth drive it will probably be possible to buy 3TB for a similar price and I will then have a full-house array totalling 7TB. By that time I'll need more than one partition (initially I specified 4TB and I'm still well within this), but the Drobo feels pretty future proof. The beauty of it is that you can start replacing the original 1TB drives with 3TB units without having to consider copying and backing up. Drobo does it all for you.
These days a cast-iron backup strategy is absolutely essential. All my records are now digitised and I have been destroying papers for the past two years, so you have to consider the unthinkable. Drobo is a major step along the way to full protection.