A busy dog is a happy dog. An easy and fun way to keep your dog busy is to teach your dog a few tricks.
Of course, you can get the same tricks offered on this app for FREE on the internet, but if you want a portable version you can carry with you then the $2.99 for the Dog Tricks- Best of 101 Dog Tricks iPhone app might be worth it. The app features step-by-step instructions with a demo video featuring dog trainer Kyra Sundance for 8 tricks including sit, down, crawl, roll over, shake hands, spin circles, and fetch. (Sundance also has a series of "101 Dog Tricks" books and DVDs.)
I've decided teaching my puppy sit and down are useful, but teaching him to spin in circles might not be the smartest idea.