It happens to me too. What I do -- and this does help -- is I gradually reduce the speed, so I walk much more slowly than I would on the street -- and then after I come to a stop, I spend a few seconds on the treadmill doing stuff. Like I'll take a sip of water, screw the top back onto my water bottle slowly, wipe sweat off my forehead, carefully fold up my towel, note down my stats in my notebook, play with my mp3 player, whatever... just try to stay there for a minute. Then I get off and walk off to whatever I'm doing next. I find that if I get off as soon as I stop, it feels like my head is moving faster than my body!! Since I have to go down a flight of stairs right away at my gym, I don't like being disoriented for that, seems a little risky!