I made some notes the other day on some of the people around me on the way home. The woman I mention below was the most "exciting":
I sat down opposite a rather large lady who was wearing a bluetooth headset - she wasn't driving the train and in fact her hands were anything other than full - she was doing nothing but she stil had this headset on. No one rang her. My suggestion, stop looking like a wannabe with no friends... Loose the headset girl.
I've seen many people around in the same situation as above who have their hands manifestly free but who are wearing a headset... Why? Because they think they're in the SAS.
In this woman's defence, I should say she had the most incredible set of finger nails - decorated in the digital equivalent of the Sistine chapel.