That's actually not too bad, as blood pressure goes. Normal is anything below 130/85, though it's better to be lower than 120/80. "High Normal" is anything below 139/89.
http://www.new-fitness.com/Blood_Pressure/numbers.html
Remember also that there are a lot of things that influence BP. Stress, exercise, lack of sleep, nerves (mine is always higher when the doc takes it... I have "white coat" syndrome). My doc always makes me sit there for ten or fifteen minutes breathing deeply before she takes mine. Otherwise I get false highs. The fact that you'd been walking before hand makes me think this may have been a false high on your systolic.
Here's some results on blood pressure numbers and what they might mean.
http://www.google.com/search?q=blood...ient=firefox-a
If it does become a concern, regular exercise is the best non-medicine thing you can do for it. Lowering sodium also can help somewhat, but they're not sure how much of an impact that really has.