Hi Kevin,
We used an organisation called Akendi ( http://www.akendi.com/usability-ucd-user-centered-design/usability-testing-company.php ) for our web re-design. The experience was very positive - they not only did the usability, but committed to a significant amount of skills & knowledge transfer. They were very thorough - no cookie cutter approach - and took care to really understand out business (a Provincial (aka State) Legislature). 
I'd be happy to discuss further.

Peter

> -----Original Message-----
> From: Code for Libraries [mailto:[log in to unmask]] On 
> Behalf Of Kevin Reiss
> Sent: January 18, 2013 4:26 PM
> To: [log in to unmask]
> Subject: [CODE4LIB] Web Usability Consultant
> 
> Hi,
> 
> We are in the process of putting together a plan to conduct a 
> comprehensive usability study for our web content and 
> services. I was wondering if anyone on the list who has 
> worked with a usability consultant or firm that they've had a 
> positive experience with would be willing to pass on a 
> recommendation. 
> 
> 
> Thanks,
> 
> Kevin Reiss
> Web Developer
> Princeton University Library
>