While not quite under “stuff I have at home” – but definitely under stuff I have my clients use – the “drobo” series of drive cases from Data Robotics, Inc. is a fantastic series of drive cases that do far more than allow you to hook up external storage or set up RAID arrays.
Most external drives are limited to the maximum size of one disk, and when your computer drives are near that maximum, backing them up with any sort of history you can dial back becomes a problem. Well, RAID is a solution to this kind of issue, but RAID is finicky to setup, and even more finicky to change or expand.
Hook up a Drobo, and slot in two drives. Now, if one of those drives fails, the other one keeps chugging with all of your data intact. All you have to do is yank the failed drive and slot in a new one, and it automagically rebuilds itself.
Need more space? Add a drive.
That’s it. No fuss, no muss, no reformatting or commands. Just. Add. A. Drive. The Drobo does all the work.
Need more space? Add another drive. Used up all your drive bays? Yank out your smallest drive and replace it with a bigger one. No need to shut it down, etc.
At every stage, the Drobo takes care of everything else.
We even had a client who’s Drobo had gone bad (the top bay failed) pull all the drives out under power, slot them into a new drive bay, and power it up. The drive rebuilt itself and is working just great.
Needless to say, I can’t recommend it highly enough. It’s expandable drive space for backups or storage, for people who don’t want to think about technical details.
Update: Over time this has become a recommendation I’ve reversed. At first, many of these worked, but over time flakiness with dealing with drives (even if you carefully shopped off the compatibility list) and network connectivity and access speeds drove us to finding other solutions.