As we've discussed here, crate-training your puppy should be one of his first obedience lessons. It lays the foundation for more advanced training, it aids greatly in house-breaking and it just plain keeps him safer when you aren't around. It's not mean—it's the right thing to do.
More recently I came across a blog post on the subject by professional retriever trainer Rick Grant on the SportDOG Brand website. It's well worth the full read, as it delves into four hunting-dog specific reasons to crate-train your dog.
My favorite point Grant makes is one I had not considered: One day you'll have to send your duck dog ahead of you for retrieves or your upland dog—be it a pointer or flusher—ahead of you to hunt.
"With those concepts in mind, what better way to reinforce the concept than sending [your dog] to his kennel?" Grant writes. "Once your dog knows what 'Kennel' means, you should be able to send him there from 10 feet, 30 feet, or really almost any distance."
Do you crate-train your dogs? Why or why not?