I'd agree with DR1... last summer we had a meeting at our field and the winds were consistently blowing what folks thought were around 20 mph. Then one of our guys showed up with a handheld anemometer, and it showed 10-12mph for what I felt were marginal flight conditions.

There's a couple of us that now take a more practical approach. If the wind is blowing our 6lb planes (H9 Arrows, Aerostar, Tiger2) off the flight tables, or it flips them over when taxiing out, it's time to stay on the ground. But I also agree with MinnFlyer... it's a kick to be ablle to land a plane "vertically" when airspeed cancels out groundspeed.