We've recently being doing a spot of psychometric testing at Team17, in order to initially help the management team understand everyone else a little more and secondly to communicate better and enhance how we work. The initial results have been pretty encouraging, it's incredible that a short 'test' gives an unnervingly accurate summary of a person's psyche.
It's been really interesting talking to sceptics and then seeing the transformation post test-results. I know a lot of people call such devices and tests low on practical use, but I'm not so sure, it just depends on how they are used; they are a tool and reference aid and not a determining factor. In particular they can help you understand someone's inner self and see where and how they'd be useful (or not!) which has its benefits on an interview level. Personally I like the fact that they can re-affirm what your concept of a person's motives and attributes are - or they can point out one or two things that perhaps hadn't been obvious.
An instance that occurred recently is that one of the guys who's had a profile at our place has been determined to simply not read verbose text and will often seek a simple, punchy overview or ask a trusted other to give them the overview.
Something like that is not always obvious and it's made me consider that in the materials I send out - perhaps there's room for me (who is known to bang out the odd verbose doc) to accompany any longer reports and docs with a short, to the point summary overview that is brief on factual detail for example. At the end of the day the whole process is about improving where we can.
Incidentally, the DISC in the subject matter refers to the common profiling system of testing DOMINANCE, INFLUENCE, STEADYNESS and COMPLIANCE in terms of character traits - the results are generally observed by looking at the scores in each (+20 through -20) which are then plotted on a graph and common patterns emerge according to those traits. Personally, I'm a high I/S in an inverted U shape, which oddly enough is summed up by a "gregarious communicator/counseller" where people & emotions are the priority rather than practical detail.
It doesn't take too much thinking to consider that someone who scores high in Steadyness and Compliance would work well in a technical, production role and those with dominance (and to a lesser degree, influence) would work well in direct management positions under pressure.
It's an interesting subject and one that certainly makes you sit up and think, there's a ton of pages on the net on the subject, just search for DISC profiling and enjoy!