We just scheduled a 3D/4D ultrasound for December 27. I will be 25w1d. I wanted to schedule it then so my sister can go with us :) Her family will be in town for Christmas for a week.
We are having it at Vision Within 4D Imaging Center in Troy, Michigan. Here is the link:
Their website has tons of examples of 3D pictures. We will purchase one of the packages that also includes a DVD of the ultrasound (which is the 4D part of it, I suppose!). We're very excited!