This article on MSNBC , written by registered dietitian Karen Collins, states that 10,000 steps is now considered a good daily exercise goal: If, by the end of the day, you've walked that many paces, whether at home, at work, or going from one to the other, you've met an important goal and deserve a pat on the back (and a nice cup of Mellow Monk green tea).
As for specific exercise goals, many health experts recommend at least 30 minutes of brisk walking or other activity each day. But one study described in the article found that a pedometer was an easier way of keeping track of one's daily progress than following a "time goal," especially when spreading a daily workout over several separate exercise opportunities throughout the day.
—Mellow Monk