You don't need to run marathons or do an hour of ab exercises a day to keep fit. Walking is easy, low-impact, and can be done anywhere, anytime, with anyone.
Basically, you should be taking 6,000 steps a day for health and 10,000 for weight-loss. Wear a Pedometer to count your steps. They're around $30 or less and can be easily concealed in your pocket. If you're trying to ditch extra pounds, aim for a daily walk of 6,000 uninterrupted steps.
Here's my pick: I like the one made by Sportline. It not only counts your steps, but you can also keep track of your distance and calories burned.
FitsTips: Wear your pedometer from the moment you wake up until you go to bed. Keep a Pedometer Journal and write down your steps. Figure out when during your day you can get more steps in.