If you don't have a dog or want another one... go to your local shelter and adopt . http://www.youtube.com/watch?feature=player_embedded&v=BWAK0J8Uhzk
One of my pup's is a rescue and the other one is a $500 pain in the arse!!!!! I rescued a dog off the side of the road in '07 but had to take him to the "no kill" shelter after two days of love and caring. It was one of the toughest things I have ever done, I cried like a baby after dropping him off. Gotta go hug my current PITA!
Adopting is always the best thing to do. My wife runs in partnership the local animal rescue and we are always looking for homes for our furry friends. I have a dog and 3 cats and my wifes partner has usually 10 cats and a few dogs. She just cant say no. If you are looking to get in shape just get a dog and walk it everyday.That works for me.