Having done a little business travel around the US, I have to say it is regional. Boston-Wash corridor more so then West coast. Big cities more so then out in the sticks. Middle aged (?) more so then the 12-20 and 40+ crowd (perhaps my wife's rationale... No sense putting paint on a wrinkled canvas?). Also job/work situation and it's expectations/dress code/peer pressures. So many factors there Max (Sorry, couldn't pass up the pun)
I tend to use shadow for reasons similar to Valwen's, an unambiguously female presentation as possible for this six footer. Which generally is my fav girlie-girl. In jeans I tend more towards just a light touch mascara