Tired of pesky people cluttering up your landscape or architectural photos? The old trick is to slow your shutter down to make anything that moves disappear. And I mean sssslllloooooowww the shutter. People moving at walking speed tend to disappear at about 25 seconds. If they stand still for a moment they'll appear as smudges, then shadows. In order to slow your shutter you'll obviously need a tripod, and in daylight a neutral density filter (probably around 10 stops). Open up the aperture and keep your ISO at 100. With shutter speeds this slow you don't need to worry about remote triggers or delays. I didn't think to use this technique on the photo above and wish I had (I was carrying a mini tripod in my bag anyway). Images of the Aya Sofia mosque in Istanbul without people are fairly rare, and it would have been easy to achieve. Consider this next time you're in a church or historic building-- don't crank the ISO in order to get the shot, drop it, prop the camera on something, and go for slow.