While working at the music and neuroimaging lab at Beth Israel/Harvard Medical School in Boston, I developed a quick online way to screen for the tonedeafness. It actually turned out to be a pretty good test to check for overall pitch perception ability. The test is purposefully made very hard, so excellent musicians rarely score above 80% correct.
Give it a try!
My score: 80.6% Correct
The site says results can be interpreted this way:
Greater than 90% correct: World-class musical abilities
Greater than 75% correct: Excellent musical abilities
Greater than 60% correct: Good musical abilities
Less than 50% correct: You may have a pitch perception deficit