I am going to respectively disagree with the members that posted that you shouldn't use a crate for "time outs". The punishment is not the crate, but rather the exclusion of interaction with you.

Jean Donaldson in her book "Dogs Are From Neptune" expresses this better than I do :

"People get very antsy about the crate suggestion as they have been indoctrinated to not associate the crate with punishment lest the dog came to hate his crate. This is unnecessarily rigid. The punishment is the removal of opportunity to interact, not being in the crate per se. If, for instance, you were hanging out together with the dog IN his crate, having an enjoyable time wrestling, cuddling or holding a bone for him to chew on and the dog misfired with its jaws, you may very well boot him OUT of the crate as consequence. Would the dog then associate being out of the crate with punishment?"

Donaldson, J. (1998). Dogs are From Neptune. Canada: Laser Multimedia Productions (pp. 90-91).

When I was dealing with Leo's play biting (it was never aggressive, just inappropriate play) - time outs in the crate saved us. He still uses his crate for sleeping and relaxing, although the door is rarely closed now.

Since adopting Penny Lane last May and having a behaviorist at my house, I have become facinated with learning the subject of animal behavior and have begun taking classes and going to seminars. I is amazing to me how much research has been done on the subject of animal behavior.

JMHO