The only real issue I see is that strapping down external drives defeats the purpose of the external drive (portability).
Somehting I did once was buy a nice little PC case. Then put drives inside it instead of individual USb cases and powered them from its power supply. Then I put some IDE to USB adapters on the back of them and stuck a USB hub inside the case. That way I had only one power cord and one USB cable.
But I've since moved away from that, now I stick my drives in USB enclosures and stick them either in a drawer or the larger stuff like CD/DVD burners I store in cheap smaller laptop sleeves on a shelf in the closet with all the blank media behind it. So when I want to burn some data I just pull out the drive and use it then put it away.

>> The only real issue I see is that strapping down external drives defeats the purpose of the external drive (portability). <<

In my case, I use the external drive because I simply need more storage. I don't use it for the portability factor. My main computer is a PowerBook G4.

I use a laptop and just stick a new drive in every so often, usually doubling the size.

I'm aware that you can upgrade a laptop disk, but you can't get more than 160GB (still too small for me), and at that size the drive is slow and expensive. For precisely the same price (enclosure is already paid for) you can get 500GB and have it be fast.