Like most families we have bought all sorts of electrical stuff over the last few years (camcorders, mobile phones, digital cameras, computers, TVs, games consoles, stereo systems etc etc).
There is ALWAYS a couple of cables extra you dont need, so I throw them in a box in my office at home.
This box is now overflowing with cables, most of which I have no idea what they are for.
Sometimes I am tempted to throw the lot away, but no doubt the day after I do that I will need one of those cables. S*ds law eh!
So they just sit there in my office gathering dust.