The problem I have with these SAT style interviews though is that they're weeding out talent unnecessarily. Personally, I tend to get brain-lock when I'm under intense scrutiny, and the stress of knowing that I'm in the middle of a potentially life altering event really isn't helping any.
The reason I think this filter is unnecessary is because I'm pretty sure that "stage fright" isn't actually a problem you'll face if you work at Google or Amazon or Microsoft or wherever. You have projects and goals and you work to complete them. Christ, you're a programmer, not John McClane. Nobody is standing around with their thumb on the detonator watching you write an algorithm for reversing a linked list.
I suppose it would be difficult to scale, but I think what would be more successful for the technical portion of the process would be a Google Code Jam style arrangement whereby you're given a problem to solve, you crunch on it for the evening, and when you've figured it out you upload your code. If it's correct and fast, perhaps you'd make a good employee...