The question of what if you could never leave comes to mind with the below video. The Infini-room in Second Life constantly adds an identical room outside of whichever door you choose to open.

This creates the effect from the point of view of the unhappy avatar of being trapped in the same room with no way to leave. There are few different uses for this that I have listed below the video:

HD Video: The Infini-Room in Second Life

Uses for the Second Life Infini-room

1. A new form of griefing in Second Life similar to trapping Second Life residents in cages.

2. Creating your own personal hell or purgatory in Second Life

3. A trap room in a particularly frustrating role playing game in Second Life.