I wanted to call your attention to Smarterer, a company recently acquired by my employer, Pluralsight. Smarterer's schtick (apart from vexing my auto-correct) is that the host crowdsourced technology assessments. In other words, the community decides what questions to ask someone in the test.
The magic is that their back-end engine, over time, figures out which questions are awesome and which ones suck, and adjusts the assessment accordingly. So as more people (especially qualified ones) take the test, the better it gets at identifying skilled people. It gives it a sort of built-in immunity against bad community-contributed questions, because those eventually filter out of the assessment that's delivered to people. It's pretty engaging, actually. I've had some fun taking some web development-oriented assessments, and surprised myself in a few places.
They've got a PowerShell assessment. Why not jump in, take it, and then add some questions of your own? Next time you need to interview someone for PowerShell chops, send 'em to Smarterer.