Individual 'days' or play time when you have multiple dogs.

Kaiser seems to have finally caught on to the whole "fetch" thing from watching Luke, so now we are able to successfully keep two balls going at a time.  I throw Luke's ball out further with the Chuck-it and then usually skim Kaiser's across the ground since he's more of a motion-chaser.  Luke is all business with fetching and never takes his eye off the game.  Kaiser tends to get more distracted and sometimes drops the ball across the yard or decides to just run around with the ball in his mouth.  I don't really care what he decides to do, as long as it's active.  If he brings the ball back, it gets thrown.  The boys are really great about sticking to their own balls and we haven't had any arguements.

I have two tie hooks attached to the deck for when I need to keep the dogs separated.  This is used mostly for our agility work, as there is no way I can get anything accomplished when there is a second dog in the way.  Nor can I have Kaiser's frisbee out with Luke in the yard, as he thinks all frisbees should be his.

They're pretty much together at all other times, though.  Agility training is their major one-on-one time with me.