Steve Sailer has a few posts on employee testing, starting with this one about companies using Hadoop and other solutions to monitor employee activity. In classic Sailer style, he continues for a couple more posts on this thread, pointing out how difficult it is to get an employee test to pass judicial scrutiny.
During my recent round of interviews, I had one company give me a general IQ test—it was basically a set of SAT sample questions. In my particular field, there are some good proxies for determining employee quality, but g is still one of the best indicators.
36 Chambers - The Legendary Journeys: Execution to the max! 