I was surprised the other day when helping another friend prepare for a test on English speaking proficiency (for foreigners to join the U.S. government). One of the applicable tests is Versant, which does this. It is a verbal test. You call a phone number, enter your ID and then do tasks including: read sentences, give one or two word answers, create sentences by reordering and linking three phrases, retell a story with as many as possible of the characters, actions and situation; and finally give your opinion about a concept (like, "Do you think children should be able to decide when and how much to study?"). The system grades you not on individual questions but gives you a general score in areas like vocabulary, pronunciation, and fluency. The problem is it is very rapid-fire so you can't really pass it unless you are close to a native. The grades can be viewed on the web in a few minutes.
On one practice test I typed what he should say live during the test, which gave him an idea of how much work he has cut out for himself to achieve a passing score.
http://www.versant.jp/e_about.html