I've had several technical phone interviews and programming challenges in the past week, and nothing has been even close to as easy as FizzBuzz. Do places actually give it out in interviews?
I only use it as a warm-up, because I understand that interviews are pretty stressful. Then I'm dumbfounded when someone who applied for the "Experienced ASP.NET/C# Developer" position can't even get through my warm-up.
We used to give it to candidates who showed up overly early to interviews. Something reasonably simple they could do waiting in reception while we got people together for the actual interview. I think the success rate was around 50% with the most common error being incorrect conditionals.