According to their website, ProtoCAM is the:
largest rapid prototyping bureau in the Eastern United States, providing a unique blend of manufacturing engineering / rapid prototyping consulting along with stereolithography and other advanced rapid prototyping techniques.
While they do not provide instant online quotes, they do accept a large variety of CAD formats, including STL. ProtoCAM offers use of an ObJet printer equipped with PolyJet technology.
The Pennsylvania-based company joins our growing list of 3D print services.