"Then I pose a software development challenge. For example, how would you implement a Web-based clone of PowerPoint? This gives me a feel for how smart they are

"Then I pose a software development challenge. For example, how would you implement a Web-based clone of PowerPoint? This gives me a feel for how smart they are, and if they know the basics of software development." A trick question, of course. The correct answer is "you don't, since Google will simply release their own which will make yours irrelevant."