Whiteboard interviews DO work - if done right. Don't ask computer science questions. Instead give the interviewee real world problems to solve. And find out how he/she attacks the problem. What he/she would look at to solve the problem. What tools he/she would use and why. The key thing is to learn how the interviewee thinks through a problem. And how well the interviewee explains his/her thinking. I have interviewed and hired people for 10+ years and can testify that this approach work.