Originally Posted by Laika

This is true for any vehicle IMO. I learned to drive in a car that had no side mirrors and as a result I ALWAYS turned my head to look, even in other cars. It's this practice that I'm trying to carryover into cycling, and I've mastered the mechanics of turning to look...my problem, really, is in assessing the information gained by the look back. Aside from the enthusiastic mirror advocacy, the most useful thing I've seen here so far from all the kind and thoughtful suggestions has been to increase the length of time I spend looking. I'm going to try to work on that.

As for the benefits of being seen as you turn your head, I agree, and yet have to say the head turn is the least noticable thing I do in traffic to communicate my intentions. I''ve largely abandoned traditional hand/arm signals in favor of big, broad, unambiguous hand/arm signals, namely a noticable wave to the motorist and then an emphatic pointing motion at the space I'm going to occupy once I move. I've gotten good results in Brooklyn & downtown Manhattan this way...most cars will back off a little, even.

Thanks again for all the advice, folks.