Belbin Team-roles were conceived by Dr Meredith Belbin. They are a personality classification style, and can be used as an alternative to the Myers-Briggs Type Indicators. They apply directly to work, and styles of working, and are less useful than MBTI as generic personality descriptors. On the other hand, Belbin not only classifies working styles, he also considers the kind of styles which will combine well together to create a strong team. For this reason I find the analysis more satisfying than MBTI, at least in a work context. Another strong advantage of the Belbin classification style is the acknowledgement that with any great strength there will normally be a matching weakness: Belbin claims that these are ok, as long as other team members can compensate.

The nine team roles are:

Plant
A strongly creative person
Coordinator
Enables other people to perform at their best
Monitor Evaluator
A good critic
Implementer
Someone who actually gets things done
Completer Finisher
The classic anal retentive detail monster
Resource Investigator
Someone imaginative and enthusiastic, one who spends a lot of time doing lunches with very senior people
Shaper
Gets other people to get things done. The slavedriver
Teamworker
The peacemaker, gets on well with everyone
Specialist
Deeply technical, a great problem-solver
You can read more about the types at http://www.belbin.com/. You can also take online assessment there, but unfortunately you have to pay for it!