I am a big fan of shredding, not for security - just for that nice buzzing sound that it makes. However, I think many people will recall having shredded something, only to regret it moments later...
I propose the following solution, the scan-0-shred. As the name suggests, it is a combined scanner
and shredder. Basically, the scanner has "transient" memory of say, 30 seconds. If you shred something by accident, simply press the "oops" button, plug in the USB cable, and retrieve the document.
Important note: the scanner unit must be placed before the shredder, otherwise it becomes the world's fastest jig-saw puzzle... [see link] World's Fastest Jigsaw Puzzle, a cross-cut shredder and scanner combined.