I wear them over the ear all the time, and it REALLY cuts out the microphonics.
When I first got the er-6i I noticed the microphonics mostly from wind hitting the wire, and from the wire rubbing on my clothing. It was really bad as it got colder and I had to wear a heavier coat.
Anyway, I started experimenting, ans started putting the wire behind my head. This wasn't bad, but still had enough noise to be a problem. Then I tried going over the ear. This pretty much eliminated the noise, but introduced yet anothe problem. With the wires going over the ear, there really wasn't a good way to keep them there. Consequently, I'd be walking down the street, and a loop of wire would loosen and go flopping off into the breeze annoying me even more.
Then I figured out a solution.
I made a little wirekeeper for when I wear them like that. I removed the shirt cilp, and pulled an old (but clean) eartip over the cord. Stretching it over the plug wasn't easy, but with a little time and patience, it made it over. Then I slid it up past the part where the wires join, so it's on the seperated wires. After that, I carefully cut the flanges off and shortened the piece that's left on there. So now when I put the wires over my ears, I just slide this piece up and the wires become more taught and stay in place. It's not an overly tight fit, but it stays in place great. No there are NO microphonics to deal with. Major improvement.
If anyones interested, I'll post pictures.
-Jeff