Here's a <a href="http://stormwerks.com/linked/pix/doorway.gif">picture</a> of some alley or back of a house somewhere. In order to get the full effect, you have to really examine the picture. In particular, look at the mattress and the rubber hose on the floor...is this a drug den? Who knows? Is that a person in the doorway, reaching for something on the floor? Who knows? But, if you wait at least 30 seconds, the creepiness will reveal itself.