Today is National Dog Day. But even if you don't have an adorable pup of your own to celebrate with, you can still observe this very important holiday. Get your weekly cry in by re-watching Homeward Bound (or even just skipping to the end). Stop by your local shelter to see if they need any volunteers. Or, just like some Instagram pics of celebrities enjoying quality time with their canines. Celebs know how to select cute companions, from puppies to old timers. Some of these dogs are so photogenic, they even have Instagram accounts of their own. Be warned, small apartment or not, staring at these pics might cause you to run out to your local adoption center and pick up a dog yourself. Think of the Instagram possibilities alone!