I recently had a job audition. It was for a programming job and yes, I did say "audition'. This was the most interesting (and unique) interview / pre-screening technique I've seen to date. I approve wholeheartedly.
The job description was unusual:
MUST take a test before the interview
While I certainly didn't expect my life to change, I was, nonetheless, intrigued. I sent my resume; I got a call back; we talked. The recruiter gave me his take on the "test" idea. The test serves two purposes. First, it provides the client company with a much more realistic picture of the applicant's abilities and skills.
Second, by getting people to commit 30 to 40 hours on a test, the company has a much better idea of the "sticking power" and motivation of the candidates. Candidates self-select before the interview. Those who aren't really qualified, aren't motivated, or simply aren't really interested, drop out before finishing the test.