I did this once with my excitable Dane/lab (100lbs)... had him in a down with my foot on the leash while a friendly (and excited) dog approached... he flipped me so quick!!! and he was just 100lbs.... so, I don't do this so much anymore - but we do practice stepping to the side (up a driveway) and watching people pass... sometimes in a sit, sometimes just a calm stand. Denna's very used to the procedure now, which helps - she knows what I want her to do (i.e. not move and just supervise the people passing by).