What is the best situation to take an HDR photo?

Question: What is the best situation to take an HDR photo!?
Best Answer - Chosen by Asker:

I am certainly no expert on HDR but here is a good article from Shutterbug magazine on it
http://www!.shutterbug!.net/equipmentrevie!.!.!.
http://www!.shutterbug!.net/equipmentrevie!.!.!.
and some other pages on it
http://www!.nicolasgenette!.com/Labo/Artic!.!.!.
http://range!.wordpress!.com/2006/07/15/mo!.!.!.Www@QuestionHome@Com

Like this one:

http://www!.flickr!.com/photos/little_pook!.!.!.

On a tripod!. With cable release!. Same aperture (so there won't be any variable in depth of field) always!. Low ISO for grain-free result!. Four photos for this one!.Www@QuestionHome@Com