It is accepted where I park (in the racks in the underground car park for my office) that everyone leaves their locks on the racks. They are the type that stand the bikes up at 45degrees, with one bike high the next low, then high etc. So etiquette is to allways leave your lock round the base of the tall stands so that whilst places swap over, everyone can get at their lock.
The parking is really secure as you can only gain entry via electronic swipe card, its got full cctv coverage and security guards manning a barrier at the exit. And its only my company in the building. Many colleagues (me included) leave trainers down there for walking to their offices which don't have undergound facilities, or all their spaces are taken. We also have a communual track pump and an honesty box that 99% of the time contains a couple of tubes, and allways has tyre levers and a handful of patches.
The honesty box is really good actually, as if you do have a tyre go down during the day, you can get yourself home without sacraficing your spare tube (if you only carry 1)