[Orgmode] hiding PROPERTIES line

[Ilya Shlyakhter]

Is there a way to hide/show the :PROPERTIES: line representing the
properties locker,
either globally or for a subtree?  I'd like to store some properties
for every entry (e.g. its creation time),
but then the :PROPERTIES: lines add too much clutter, even in the
drawer-collapsed state.
Is there a way to hide/show them just like the closed outline subtrees
are hidden/shown?
thanks,
ilya