I have to brag a little and say my dogs are all very good at this exercise. We were at the mall this afternoon. My dogs are a month away from going into class, and they have done all the foundation work with this exercise and are now smack in the middle of generalizing to different environments and different types of chairs. It was a great thrill to me to be able to say "Chair!" and watch my dog scan to the left and to the right, lock in on a chair, and zoom straight to the chair and put his or her nose on the chair seat. They can find all different kinds of chairs -- armchairs, benches, regular kitchen chairs, anything, whatever type of seat is the first available when I say the magic word "Chair". I know, this seems like a small thrill after watching dogs learn how to judge moving traffic and other complex things, but for some reason I just love watching them do it.
The only thing I have to be careful of is overusing the command because I like it so much. I only had one dog today out of four show me a chair when I hadn't asked him to find me one, but if I do this exercise too frequently it is totally possible that the dogs will just start leaving the straight line of travel to find me a chair without being asked, in the hopes of seeing my joyful response. That would be counterproductive, annoying instead of helpful to the dog's future partner. So -- big sigh -- I will limit my use of "Chair" to only the times when I'm legitimately looking for one.