Via Kristina's blog, a neat test to determine if you are tone deaf.
I love to sing. If I do it near my students, E. covers my mouth and says "good job." (In other words, "shut up.")
For what it's worth, I scored:
64% correct, which is the 12th percentile, and considered "low normal."
(Edited to add the actual link inside the post. I am brain dead.)