Found them through classified ads:
http://classifieds.chinadaily.com

Ended up at the agency site:
http://www.massageinri.com/
The mobile version is very different from the desktop version, and all I had was my phone to research.

Called from my mobile and requested an appointment from the English speaking operator.  They wanted to know the city, my name, room number, hotel, and hotel phone number.  Provided those and within 5 minutes I had a text noting that someone could be there within 30 minutes, and the rates.

Confirmed via text and they notified me of arrival time.  The girl who arrived was not the one in pictures, nor on the phone, but was very close.  Fun time had by all.  Don't know her name, and she has no ad, otherwise I'd put up a review for her.

Would recommend the agency again given it was a last minute availability on my part, but would be more direct in asking for a certain person.  They seem to operate in the areas around Shanghai, so if you're in that area I'd consider them an option.