Just listened to this speech, which I probably should have a long time ago. Steve Jobs certainly qualifies as a half bad boy and so I really should link to his speech here.
Iris Diaphragm Microscope
7 months ago
...from the "Half Bad Boy Plus Protocol" as defined in "Dating Design Patterns" (ISBN 0-9743120-0-2) ppg. 53-56 - guys that are just bad enough to attract women but not so bad that they are jerks to them.