Including a short in a real-world circuit
I worked with a guy who liked to do this: 







simulate this circuit &ndash; Schematic created using CircuitLab

In normal operation the LED is short circuited. If the fuse blows you've got a nice indicator to tell you why your circuit suddenly stopped working.

I can't say I'm 100% sure of the wisdom of continuing to run current through the load once it's had a fault that makes it blow a fuse though.