The Black Book of Outsourcing, compiled by Douglas Brown and Scott Wilson, contains its 2007 survey of outsourcing vendors. That publication contains a category for legal process outsourcers, the fourth ranked of which is LawScribe. I have not seen the book, but read about it recently.
According to LawScribe’s Mark Ross and his post of July 3, 2007, the survey also includes a category for legal document process outsourcing providers, with at least nine service providers (See my post of June 11, 2007 #3 and references cited on offshoring.). If someone could send me a table of contents, I will post more on this resource.