I found this webpage last week, it has several listening/hearing tests that are quite easy to take, and give some interesting results. They attempt to measure adaptive pitch, rhythm, and tone deafness (check the right hand column for links to each test).
Adaptive Pitch: Measure your pitch perception abilities
My own scores:
Adaptive Pitch - 1.1625Hz
Rhythm - 80%
Tone - 75%
Edit: Musical Visual Score:
80% Overall
Sub-scores:
78.3%
83.5%
80.7%
78.5%
75.1%
