Brandon Savage has a suggestion for those interviewing developers for positions at their company - forget the coding test.
One thing I've noticed in hunting for a job recently is the number of companies that insist that you write them a code sample to spec. Not just any code sample, but a fully functional, complete application. This is absurd, for several reasons.
He suggests that, while submitting example code or taking a test as a part of the interview process can be a "first line" to be sure the person knows the language, they shouldn't be considered useful much beyond that. He likens it to people in other trades (like a plumber or electrician) to do their job before they can do their job...for you. Brandon suggests that the real key to a developer - how well they can learn - just can't be measured by a test like this.