Any self-respecting Mac-geek knows what "Time Machine" is in the up and coming Leopard-- the automatic file backup wizard that takes data from one mac in your network, and seamlessly backs it up (in an ideal configuration) to another Mac on your network.

Now that's pretty darn handy, but it sure would be nice if that other "backup Mac" had a few features.

For example, redundancy. If the backup Mac's hard drive fails, you could lose all of your Time Machine'd data, not to mention the data on that Mac.

Another example, storage space. If you plan on having one or more machines sending their daily diffs to this "backup Mac" (my laptops both together have about 120GB of data, and my backup Mac's capacity is only 300GB, including an external drive), you'll be limited in "how far back" Time Machine will be able to store your backups.

What does this have to do with "Drobo" (which I have told you nothing about so far)?

Well, Drobo is billed as "The World's First Storage Robot". It's basically a "four slot" SATA hard drive array that appears to your computer as if it was a single attached USB drive.

The huge advantage over technologies like RAID is that this is simply consumer-level plug-and-play.

Hot swap the drives into the unit, regardless of capacity and speed, Drobo takes care of the rest.

While your total capacity is limited by the smallest drive in the Drobo (check out "drobolator"), if you need more capacity, they suggest you go to the store and buy the most storage for your dollar. Excess capacity is reserved for "future expansion" (meaning when you buy a larger drive and retire your smaller drives from the array).

With 1TB drives as inexpensive as ~$400, you can get 4TB of data backup capacity for about $2K. Not bad. If all you need is 500GB, two 250GB drives cost ~$90 each. The Drobo is $499, so for around $800 you can get a half terabyte of redundant backup storage:

Drobo: $499
250GB WD Caviar HD: $90
250GB WD Caviar HD: $90
MacOS X Leopard: $130