In reply to Martin W:
Since I cycle to work every day*, I come into work not wearing 'pants' every day; cycling shorts every day, even in winter. Well, pretty much the same degree of 'not wearing pants' as most of the people in those pictures...
* well, not at the moment; I am currently at n-5, thanks to the local scrotes who stole my 15-yr-old cycle-to-work clunker.