I would like to request a command to put a window at the end of the window-switching order.  It would be analogous to Emacs's bury-buffer command.  I would use it for status windows, like a download manager or an IM buddy list.

IRC conversation:

14:06:13 <iaindalton> Think it's OK to report lower-window not putting the window at the end of the end of the window-switching order as a bug?
14:06:40 <adamk> I wouldn't necessarily consider that a bug.
14:07:00 <adamk> I've never once thought about a windows layer impacting it's position in the switchers.
14:07:56 <iaindalton> Then would a feature request asking for a way to put a window at the end of the switching order be the way to go?
14:09:03 <iaindalton> adamk: if the only way you switch windows is with alt-tab, their z-order corresponds to their window-switching order, right?
14:11:06 <adamk> I've always thought that the alt-tab order should correspond to the last time you accessed a window.  Which may not have anything to do with their z-order.
14:11:16 <adamk> But you could certainly request that on the forums.
14:14:03 <iaindalton> Say you have an app that shows the status of something (e.g. a download manager or IM buddy list).  You occasionally check it, but then you want it out of your hair so you'd like to `bury' it.  That's what I thought lower-window did, but it doesn't.