Keep up the posting, I need more ideas to keep mine busy =)
Our cattle dogs are a little over a year and a half old, and I think they can make everything into a game. My girl loves fetch, and will play for hours on end! My boy prefers just chasing the ball, and isn't really that good at giving it back to Mom so she can throw it again, lol.
True to their breed, they like herding games, too. During the summer months (and on non-windy days), I have a handful of huge exercise balls that they like to "herd" in the yard. Mom plays by kicking the balls out of the group, and they have to bring them back.
Pickle-in-the-middle is also always popular -- a version of fetch where Ash, the boy, is usually the pickle-in-the-middle that Ella and I try to keep the ball from.
"The dog is a gentleman; I hope to go to his heaven, not man's."
- Mark Twain, Letter to W D Howells, 4/2/1899