As I've mentioned before, many experts suggest walking 10,000 steps a day. Depending on how far apart your steps are, that's around 5 miles according to the Walking Site. This may seem daunting...but it can add up fast if you make little efforts. Work up to it slowly over time as needed and you'll be surprised at how much you can end up doing.
You don't have to pay for a pedometer though - simply request this one from Nature's Bounty for free! (while supplies last, they say)
Do you use a pedometer?