I was reading about something interesting today. A cheap chinese knock off a portable hard drive with an interesting feature. It appears to have an infinitely large capacity.
So with a normal hard drive you plug it in (typically via USB), copy some data into it and then unplug it. A later time you plug it back in and you can see the data you've copied into it. This drive is different however - you can store data in it. But the drive only remembers the last 128mbs!
Think of this as a pocket with a hole in it. You keep trying to put coins in it, but it always falls out!
Trolling is a art