In case you missed "Hugo", the Oscar winning film from last year, the last cut of the movie is about 2 minutes long, and is seemingly a single steadicam shot. In this behind the scenes video, we see the point of view from a small wide angle camera mounted on top of the steadicam itself, and you can see how something like this is pulled off. You can even hear Larry McConkey take a sigh of relief when he finishes the move. Hit the jump for the scene from the movie.
As someone who has done steadicam work, operating a heavy rig for even just a few small clips can be very taxing and take tremendous effort and balance from your entire body to do right. Much respect to working pros doing shots like this, as smooth as this.