There are various companies offering assessment services.  Below are details of these.

CEC Europe: Base 1 (U.K. based, delivered worldwide)

Ciber - Service Management Assessment Analysis (Norway)

Fox IT: Online Assessment (Web based)

KMF Advance: IT Service Management Assessment (Australia)

Microsoft: MOF Self Assessment Tool (Web based)

Northallan: Service Management Assessment and Re-assessment Tool (SMART)

OGC - Self Assessment - now hosted by the ITSMF (Web based)

Pink Roccade: Pink Scan (U.K.)

Do you have an assessment service you would like to see here.  Please let us know.